Dr. Marco Perez's research goal is to better understand the fundamental causes of cardiovascular disease through the study of genetics and epidemiology. His group studies the genetic variations and environmental exposures that are associated with conditions such as atrial fibrillation and heart failure. He has led the studies of atrial fibrillation in Women's Health Initiative, one of the largest nation-wide population-based cohorts. He is interested in understanding the paradox that atrial fibrillation is less common in African Americans and Hispanics, despite a greater burden of risk factors such as hypertension. As director of the Stanford Inherited Arrhythmia Clinic, he evaluates families with rare inherited arrhythmias associated with sudden death such as Long QT and Brugada Syndromes and explores their links with novel genes. He also studies how best to use the electrocardiogram to identify patients at risk for atrial fibrillation and athletes at risk for life-threatening arrhythmias due to conditions such as hypertrophic cardiomyopathy. His genetic studies have led to the discovery of promising novel therapeutic targets that his group is now studying at a functional level. Dr. Perez receives funding from NIH, the Robert Wood Johnson Foundation, AHA, Stanford Cardiovascular Institute and the Stanford SPARK program.

Clinical Focus

  • Atrial Fibrillation
  • Arrhythmias, Cardiac
  • Channelopathies (Long QT, Brugada, CPVT)
  • Clinical Cardiac Electrophysiology

Academic Appointments

Administrative Appointments

  • Director, Stanford Inherited Cardiac Arrhythmia Clinic (2013 - Present)

Honors & Awards

  • SPARK Award, Stanford University (2014-2015)
  • Department of Medicine Teaching Award, Stanford University (2014)
  • Finalist, FGTB Young Investigator Award, American Heart Association (2013)
  • Harold Amos Faculty Development Award, Robert Wood Johnson Foundation (2012-2016)
  • Fellow to Faculty Award, American Heart Association (2011-2016)
  • Loan Repayment Program Award, NIH (20010-2014)
  • Dean's Fellow Research Award, Stanford University (2006-2008)
  • National Research Service Award, NIH (2006-2008)

Boards, Advisory Committees, Professional Organizations

  • Member, AHA Research Committe (2014 - Present)
  • Advocacy Ambassador, AHA FGTB Leadership Committee (2013 - Present)
  • Medical Director, Racing Hearts Community AED Program (2014 - Present)

Professional Education

  • Fellowship:Stanford University Medical Center (2010) CA
  • Fellowship:Stanford University School of Medicine (2007) CA
  • Residency:Massachusetts General Hospital (2004) MA
  • Internship:Massachusetts General Hospital (2002) MA
  • Medical Education:Harvard University Health Services (2001) MA
  • Board Certification: Clinical Cardiac Electrophysiology, American Board of Internal Medicine (2011)
  • Board Certification: Cardiovascular Disease, American Board of Internal Medicine (2007)
  • Board Certification: Internal Medicine, American Board of Internal Medicine (2004)
  • Fellowship, Stanford, Electrophysiology (2010)
  • Fellowship, Stanford, Cardiology (2007)
  • Residency, Maassachusetts General Hospital, Internal Medicine (2004)

Research & Scholarship

Clinical Trials

  • Attain Performa(TM) Quadripolar Lead Study Recruiting

    The purpose of the study is to evaluate the safety and efficacy of the Medtronic Attain Performa Quadripolar Leads (Model 4298, 4398, and 4598) during and post the implant procedure. This study will also assess the interactions of the Attain Performa leads with the entire Medtronic CRT-D system.

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Graduate and Fellowship Programs


All Publications

  • Systematic Comparison of Digital Electrocardiograms From Healthy Athletes and Patients With Hypertrophic Cardiomyopathy. Journal of the American College of Cardiology Bent, R. E., Wheeler, M. T., Hadley, D., Knowles, J. W., Pavlovic, A., Finocchiaro, G., Haddad, F., Salisbury, H., Race, S., Shmargad, Y., Matheson, G. O., Kumar, N., Saini, D., Froelicher, V., Ashley, E., Perez, M. V. 2015; 65 (22): 2462-2463

    View details for DOI 10.1016/j.jacc.2015.03.559

    View details for PubMedID 26046742

  • Feasibility of Extended Ambulatory Electrocardiogram Monitoring to Identify Silent Atrial Fibrillation in High-risk Patients: The Screening Study for Undiagnosed Atrial Fibrillation (STUDY-AF) CLINICAL CARDIOLOGY Turakhia, M. P., Ullal, A. J., Hoang, D. D., Than, C. T., Miller, J. D., Friday, K. J., Perez, M. V., Freeman, J. V., Wang, P. J., Heidenreich, P. A. 2015; 38 (5): 285-292


    Identification of silent atrial fibrillation (AF) could prevent stroke and other sequelae.Screening for AF using continuous ambulatory electrocardiographic (ECG) monitoring can detect silent AF in asymptomatic in patients with known risk factors.We performed a single-center prospective screening study using a wearable patch-based device that provides up to 2 weeks of continuous ambulatory ECG monitoring (iRhythm Technologies, Inc.). Inclusion criteria were age ≥55 years and ≥2 of the following risk factors: coronary disease, heart failure, hypertension, diabetes, sleep apnea. We excluded patients with prior AF, stroke, transient ischemic attack, implantable pacemaker or defibrillator, or with palpitations or syncope in the prior year.Out of 75 subjects (all male, age 69 ± 8.0 years; ejection fraction 57% ± 8.7%), AF was detected in 4 subjects (5.3%; AF burden 28% ± 48%). Atrial tachycardia (AT) was present in 67% (≥4 beats), 44% (≥8 beats), and 6.7% (≥60 seconds) of subjects. The combined diagnostic yield of sustained AT/AF was 11%. In subjects without sustained AT/AF, 11 (16%) had ≥30 supraventricular ectopic complexes per hour.Outpatient extended ECG screening for asymptomatic AF is feasible, with AF identified in 1 in 20 subjects and sustained AT/AF identified in 1 in 9 subjects, respectively. We also found a high prevalence of asymptomatic AT and frequent supraventricular ectopic complexes, which may be relevant to development of AF or stroke. If confirmed in a larger study, primary screening for AF could have a significant impact on public health.

    View details for DOI 10.1002/clc.22387

    View details for Web of Science ID 000354748000005

    View details for PubMedID 25873476

  • Computerized Q wave dimensions in athletes and hypertrophic cardiomyopathy patients JOURNAL OF ELECTROCARDIOLOGY Bent, R. E., Wheeler, M. T., Hadley, D., Froelicher, V., Ashley, E., Perez, M. V. 2015; 48 (3): 362-367


    There is controversy regarding Q wave criteria for assessing risk for hypertrophic cardiomyopathy (HCM) in young athletes.The 12-lead ECGs from Preparticipation screening in healthy athletes and patients with HCM were studied retrospectively. All 12 leads were measured using the same automated ECG analysis program.There were a total of 225 HCM patients and 1124 athletes with 12-lead electrocardiograms available for analysis. Athletes were on average 20 years of age, 65% were male and 24% were African-American. Patients with HCM were on average 51 years of age, 56% were male and 5.8% were African-American. Q waves by either amplitude, duration or area criteria were more prevalent in males than females, in lateral leads than inferior and in HCM patients than athletes. The most striking difference in Q waves between the groups was in Limb lead I and in the females. Tall, skinny Q waves were rare in athletes and had the highest prevalence of only 3.7% in male HCM patients.Q waves are more common in males compared to females and in patients with HCM compared to athletes. Q waves of 30 ms or more in limb lead I appear to offer the greatest discriminatory value for separating patients with HCM from athletes.

    View details for DOI 10.1016/j.jelectrocard.2015.01.009

    View details for Web of Science ID 000354343100013

    View details for PubMedID 25732098

  • Cardiopulmonary responses and prognosis in hypertrophic cardiomyopathy: a potential role for comprehensive noninvasive hemodynamic assessment. JACC. Heart failure Finocchiaro, G., Haddad, F., Knowles, J. W., Caleshu, C., Pavlovic, A., Homburger, J., Shmargad, Y., Sinagra, G., Magavern, E., Wong, M., Perez, M., Schnittger, I., Myers, J., Froelicher, V., Ashley, E. A. 2015; 3 (5): 408-418


    The study sought to discover the key determinants of exercise capacity, maximal oxygen consumption (oxygen uptake [Vo2]), and ventilatory efficiency (ventilation/carbon dioxide output [VE/Vco2] slope) and assess the prognostic potential of metabolic exercise testing in hypertrophic cardiomyopathy (HCM).The intrinsic mechanisms leading to reduced functional tolerance in HCM are unclear.The study sample included 156 HCM patients consecutively enrolled from 2007 to 2012 with a complete clinical assessment, including rest and stress echocardiography and cardiopulmonary exercise test (CPET) with impedance cardiography. Patients were also followed for the composite outcome of cardiac-related death, heart transplant, and functional deterioration leading to septal reduction therapy (myectomy or septal alcohol ablation).Abnormalities in CPET responses were frequent, with 39% (n = 61) of the sample showing a reduced exercise tolerance (Vo2 max <80% of predicted) and 19% (n = 30) characterized by impaired ventilatory efficiency (VE/Vco2 slope >34). The variables most strongly associated with exercise capacity (expressed in metabolic equivalents), were peak cardiac index (r = 0.51, p < 0.001), age (r = -0.25, p < 0.01), male sex (r = 0.24, p = 0.02), and indexed right ventricular end-diastolic area (r = 0.31, p = 0.002), resulting in an R(2) of 0.51, p < 0.001. Peak cardiac index was the main predictor of peak Vo2 (r = 0.61, p < 0.001). The variables most strongly related to VE/VCO2 slope were E/E' (r = 0.23, p = 0.021) and indexed left atrial volume (LAVI) (r = 0.34, p = 0.005) (model R(2) = 0.15). The composite endpoint occurred in 21 (13%) patients. In an exploratory analysis, 3 variables were independently associated with the composite outcome (mean follow-up 27 ± 11 months): peak Vo2 <80% of predicted (hazard ratio: 4.11; 95% confidence interval [CI]: 1.46 to 11.59; p = 0.008), VE/Vco2 slope >34 (hazard ratio: 3.14; 95% CI: 1.26 to 7.87; p = 0.014), and LAVI >40 ml/m(2) (hazard ratio: 3.32; 95% CI: 1.08 to 10.16; p = 0.036).In HCM, peak cardiac index is the main determinant of exercise capacity, but it is not significantly related to ventilatory efficiency. Peak Vo2, ventilatory inefficiency, and LAVI are associated with an increased risk of major events in the short-term follow-up.

    View details for DOI 10.1016/j.jchf.2014.11.011

    View details for PubMedID 25863972

  • Limitations of Current AHA Guidelines and Proposal of New Guidelines for the Preparticipation Examination of Athletes. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine Dunn, T. P., Pickham, D., Aggarwal, S., Saini, D., Kumar, N., Wheeler, M. T., Perez, M., Ashley, E., Froelicher, V. F. 2015


    To examine the prevalence of athletes who screen positive with the preparticipation examination guidelines from the American Heart Association, the AHA 12-elements, in combination with 3 screening electrocardiogram (ECG) criteria.Observational cross-sectional study.Stanford University Sports Medicine Clinic.Total of 1596 participants, including 297 (167 male; mean age, 16.2 years) high school athletes, 1016 (541 male; mean age, 18.8 years) collegiate athletes, and 283 (mean age, 26.3 years) male professional athletes.Athletes were screened using the 8 personal and family history questions from the AHA 12-elements. Electrocardiograms were obtained for all participants and interpreted using Seattle criteria, Stanford criteria, and European Society of Cardiology (ESC) recommendations.Approximately one-quarter of all athletes (23.8%) had at least 1 positive response to the AHA personal and family history elements. High school and college athletes had similar rates of having at least 1 positive response (25.9% vs 27.4%), whereas professional athletes had a significantly lower rate of having at least 1 positive response (8.8%, P < 0.05). Females reported more episodes of unexplained syncope (11.4% vs 7.5%, P = 0.017) and excessive exertional dyspnea with exercise (11.1% vs 6.1%, P = 0.001) than males. High school athletes had more positive responses to the family history elements when compared with college athletes (P < 0.05). The percentage of athletes who had an abnormal ECG varied between Seattle criteria (6.0%), Stanford criteria (8.8%), and ESC recommendations (26.8%).Many athletes screen positive under current screening recommendations, and ECG results vary widely by interpretation criteria.In a patient population without any adverse cardiovascular events, the currently recommended AHA 12-elements have an unacceptably high rate of false positives. Newer screening guidelines are needed, with fewer false positives and evidence-based updates.

    View details for DOI 10.1097/JSM.0000000000000203

    View details for PubMedID 25915146

  • Race and ethnicity, obesity, metabolic health, and risk of cardiovascular disease in postmenopausal women. Journal of the American Heart Association Schmiegelow, M. D., Hedlin, H., Mackey, R. H., Martin, L. W., Vitolins, M. Z., Stefanick, M. L., Perez, M. V., Allison, M., Hlatky, M. A. 2015; 4 (5)


    It is unclear whether obesity unaccompanied by metabolic abnormalities is associated with increased cardiovascular disease risk across racial and ethnic subgroups.We identified 14 364 postmenopausal women from the Women's Health Initiative who had data on fasting serum lipids and serum glucose and no history of cardiovascular disease or diabetes at baseline. We categorized women by body mass index (in kg/m(2)) as normal weight (body mass index 18.5 to <25), overweight (body mass index 25 to <30), or obese (body mass index ≥30) and by metabolic health, defined first as the metabolic syndrome (metabolically unhealthy: ≥3 metabolic abnormalities) and second as the number of metabolic abnormalities. We used Cox proportional hazards regression to assess associations between baseline characteristics and cardiovascular risk. Over 13 years of follow-up, 1101 women had a first cardiovascular disease event (coronary heart disease or ischemic stroke). Among black women without metabolic syndrome, overweight women had higher adjusted cardiovascular risk than normal weight women (hazard ratio [HR] 1.49), whereas among white women without metabolic syndrome, overweight women had similar risk to normal weight women (HR 0.92, interaction P=0.05). Obese black women without metabolic syndrome had higher adjusted risk (HR 1.95) than obese white women (HR 1.07; interaction P=0.02). Among women with only 2 metabolic abnormalities, cardiovascular risk was increased in black women who were overweight (HR 1.77) or obese (HR 2.17) but not in white women who were overweight (HR 0.98) or obese (HR 1.06). Overweight and obese women with ≤1 metabolic abnormality did not have increased cardiovascular risk, regardless of race or ethnicity.Metabolic abnormalities appeared to convey more cardiovascular risk among black women.

    View details for DOI 10.1161/JAHA.114.001695

    View details for PubMedID 25994446

  • P-Wave Characteristics on Routine Preoperative Electrocardiogram Improve Prediction of New-Onset Postoperative Atrial Fibrillation in Cardiac Surgery JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Wong, J. K., Lobato, R. L., Pinesett, A., Maxwell, B. G., Mora-Mangano, C. T., Perez, M. V. 2014; 28 (6): 1497-1504


    To test the hypothesis that including preoperative electrocardiogram (ECG) characteristics with clinical variables significantly improves the new-onset postoperative atrial fibrillation prediction model.Retrospective analysis.Single-center university hospital.Five hundred twenty-six patients,≥18 years of age, who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement/repair, or a combination of valve surgery and coronary artery bypass grafting requiring cardiopulmonary bypass.Retrospective review of medical records.Baseline characteristics and cardiopulmonary bypass times were collected. Digitally-measured timing and voltages from preoperative electrocardiograms were extracted. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Two hundred eight (39.5%) patients developed postoperative atrial fibrillation. Clinical predictors were age, ejection fraction<55%, history of atrial fibrillation, history of cerebral vascular event, and valvular surgery. Three ECG parameters associated with postoperative atrial fibrillation were observed: Premature atrial contraction, p-wave index, and p-frontal axis. Adding electrocardiogram variables to the prediction model with only clinical predictors significantly improved the area under the receiver operating characteristic curve, from 0.71 to 0.78 (p<0.01). Overall net reclassification improvement was 0.059 (p = 0.09). Among those who developed postoperative atrial fibrillation, the net reclassification improvement was 0.063 (p = 0.03).Several p-wave characteristics are independently associated with postoperative atrial fibrillation. Addition of these parameters improves the postoperative atrial fibrillation prediction model.

    View details for DOI 10.1053/j.jvca.2014.04.034

    View details for Web of Science ID 000346758800011

    View details for PubMedID 25263779

  • Evidence of Heterogeneity by Race/Ethnicity in Genetic Determinants of QT Interval EPIDEMIOLOGY Seyerle, A. A., Young, A. M., Jeff, J. M., Melton, P. E., Jorgensen, N. W., Lin, Y., Carty, C. L., Deelman, E., Heckbert, S. R., Hindorff, L. A., Jackson, R. D., Martin, L. W., Okin, P. M., Perez, M. V., Psaty, B. M., Soliman, E. Z., Whitsel, E. A., North, K. E., Laston, S., Kooperberg, C., Avery, C. L. 2014; 25 (6): 790-798
  • Molecular diagnosis of long QT syndrome at 10 days of life by rapid whole genome sequencing HEART RHYTHM Priest, J. R., Ceresnak, S. R., Dewey, F. E., Malloy-Walton, L. E., Dunn, K., Grove, M. E., Perez, M. V., Maeda, K., Dubin, A. M., Ashley, E. A. 2014; 11 (10): 1707-1713
  • Association Between Success Rate and Citation Count of Studies of Radiofrequency Catheter Ablation for Atrial Fibrillation Possible Evidence of Citation Bias CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES Perino, A. C., Hoang, D. D., Holmes, T. H., Santangeli, P., Heidenreich, P. A., Perez, M. V., Wang, P. J., Turakhia, M. P. 2014; 7 (5): 687-692
  • Obesity, physical activity, and their interaction in incident atrial fibrillation in postmenopausal women. Journal of the American Heart Association Azarbal, F., Stefanick, M. L., Salmoirago-Blotcher, E., Manson, J. E., Albert, C. M., LaMonte, M. J., Larson, J. C., Li, W., Martin, L. W., Nassir, R., Garcia, L., Assimes, T. L., Tharp, K. M., Hlatky, M. A., Perez, M. V. 2014; 3 (4)


    Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased risk of stroke and death. Obesity is an independent risk factor for AF, but modifiers of this risk are not well known. We studied the roles of obesity, physical activity, and their interaction in conferring risk of incident AF.The Women's Health Initiative (WHI) Observational Study was a prospective observational study of 93 676 postmenopausal women followed for an average of 11.5 years. Incident AF was identified using WHI-ascertained hospitalization records and diagnostic codes from Medicare claims. A multivariate Cox's hazard regression model adjusted for demographic and clinical risk factors was used to evaluate the interaction between obesity and physical activity and its association with incident AF. After exclusion of women with prevalent AF, incomplete data, or underweight body mass index (BMI), 9792 of the remaining 81 317 women developed AF. Women were, on average, 63.4 years old, 7.8% were African American, and 3.6% were Hispanic. Increased BMI (hazard ratio [HR], 1.12 per 5-kg/m(2) increase; 95% confidence interval [CI], 1.10 to 1.14) and reduced physical activity (>9 vs. 0 metabolic equivalent task hours per week; HR, 0.90; 95% CI, 0.85 to 0.96) were independently associated with higher rates of AF after multivariate adjustment. Higher levels of physical activity reduced the AF risk conferred by obesity (interaction P=0.033).Greater physical activity is associated with lower rates of incident AF and modifies the association between obesity and incident AF.

    View details for DOI 10.1161/JAHA.114.001127

    View details for PubMedID 25142057

  • Exercise capacity and paroxysmal atrial fibrillation in patients with hypertrophic cardiomyopathy HEART Azarbal, F., Singh, M., Finocchiaro, G., Vy-Van Le, V. V., Schnittger, I., Wang, P., Myers, J., Ashley, E., Perez, M. 2014; 100 (8): 624-630


    Atrial fibrillation (AF) is the most common arrhythmia among patients with hypertrophic cardiomyopathy (HCM). The relationship between paroxysmal AF and exercise capacity in this population is incompletely understood.Patients with HCM underwent symptom-limited cardiopulmonary testing with expired gas analysis at Stanford Hospital between October 2006 and October 2012. Baseline demographics, medical histories and resting echocardiograms were obtained for all subjects. Diagnosis of AF was established by review of medical records and baseline ECG. Those with paroxysmal AF were in sinus rhythm at the time of cardiopulmonary testing with expired gas analysis. Exercise intolerance was defined as peak VO2<20 mL/kg/min. We used multivariate logistic regression to evaluate the association between exercise intolerance and paroxysmal AF.Among the 265 patients recruited, 55 had AF (28 paroxysmal and 27 permanent). Compared with those without AF, subjects with paroxysmal AF were older, more likely to use antiarrhythmic and anticoagulant medications, and had larger left atria. Patients with paroxysmal AF achieved lower peak VO2 (21.9±9.2 mL/kg/min vs 26.9±10.8 mL/kg/min, p=0.02) and were more likely to have exercise intolerance (61% vs 28%, p<0.001) compared with those without AF. After adjustment for age, sex and body mass index (BMI) exercise intolerance remained significantly associated with paroxysmal AF (OR 4.65, 95% CI 1.83 to 11.83, p=0.001).Patients with HCM and paroxysmal AF demonstrate exercise intolerance despite being in sinus rhythm at the time of exercise testing.

    View details for DOI 10.1136/heartjnl-2013-304908

    View details for Web of Science ID 000333672600008

    View details for PubMedID 24326897

  • Latent Obstruction and Left Atrial Size Are Predictors of Clinical Deterioration Leading to Septal Reduction in Hypertrophic Cardiomyopathy JOURNAL OF CARDIAC FAILURE Finocchiaro, G., Haddad, F., Pavlovic, A., Sinagra, G., Schnittger, I., Knowles, J. W., Perez, M., Magavern, E., Myers, J., Ashley, E. 2014; 20 (4): 236-243


    Exercise echocardiography is a reliable tool to assess left ventricular (LV) dynamic obstruction in hypertrophic cardiomyopathy (HCM). The aim of this study was to determine the role of exercise echocardiography in the evaluation of latent obstruction and in predicting clinical deterioration in HCM patients.We considered 283 HCM patients studied with exercise echocardiography. The end point was clinical deterioration leading to septal reduction (myectomy or alcohol septal ablation). LV latent obstruction was present at enrollment in 67 patients (24%). During a mean follow-up of 42 ± 31 months, 42 patients had clinical deterioration leading to septal reduction therapy: in 12/67 (22%) patients with a latent obstruction at enrollment, in 28/84 (33%) patients with obstruction at rest, and in 2/132 (1.5%) with obstruction neither at rest or during stress. Multivariate analysis identified the following variables as independently associated with the end point: LV gradient >30 mm Hg at rest (hazard ratio [HR] 2.56, 95% CI 1.27-5.14; P = .009), LV gradient >30 mm Hg during stress (HR 4.96, 95% CI 1.81-13.61; P = .002), and indexed left atrial volume (LAVi ) >40 mL/m(2) (HR 2.86, 95% CI 1.47-5.55; P = .002). In patients with a latent obstruction, the strongest independent predictor of outcome was LAVi >40 mL/m(2) (HR 3.75, 95% CI 1.12-12.51; P = .032).Assessment of LV gradient during stress with exercise echocardiography is an important tool for the evaluation of latent obstruction in HCM and may have a role in risk stratification of these patients.

    View details for DOI 10.1016/j.cardfail.2014.01.014

    View details for Web of Science ID 000334650600003

  • Patterns and prognosis of all components of the J-wave pattern in multiethnic athletes and ambulatory patients AMERICAN HEART JOURNAL Muramoto, D., Yong, C. M., Singh, N., Aggarwal, S., Perez, M., Ashley, E., Hadley, D., Froelicher, V. 2014; 167 (2): 259-266


    Despite recent concern about the significance of the J-wave pattern (also often referred to as early repolarization) and the importance of screening in athletes, there are limited rigorous prognostic data characterizing the 3 components of the J-wave pattern (ST elevation, J waves, and QRS slurs). We aim to assess the prevalence, patterns, and prognosis of the J-wave pattern among both stable clinical and athlete populations.We retrospectively studied 4,041 electrocardiograms from a multiethnic clinical population from 1997 to 1999 at the Veterans Affairs Palo Alto Health Care System. We also examined preparticipation electrocardiograms of 1,114 Stanford University varsity athletes from 2007 to 2008. Strictly defined criteria for components of the J-wave pattern were examined. In clinical subjects, prognosis was assessed using the end point of cardiovascular death after 7 years of follow-up.Components of the J-wave pattern were most prevalent in males; African Americans; and, particularly, athletes, with the greatest variations demonstrated in the lateral leads. ST elevation was the most common. Inferior J waves and slurs, previously linked to cardiovascular risk, were observed in 9.6% of clinical subjects and 12.3% of athletes. J waves, slurs, or ST elevation was not associated with time to cardiovascular death in clinical subjects, and ST-segment slope abnormalities were not prevalent enough in conjunction with them to reach significance.J waves, slurs, or ST elevation was not associated with increased hazard of cardiovascular death in our large multiethnic, ambulatory population. Even subsets of J-wave patterns, recently proposed to pose a risk of arrhythmic death, occurred at such a high prevalence as to negate their utility in screening.

    View details for DOI 10.1016/j.ahj.2013.10.027

    View details for Web of Science ID 000329761200019

  • Prevalence and Clinical Correlates of Right Ventricular Dysfunction in Patients With Hypertrophic Cardiomyopathy AMERICAN JOURNAL OF CARDIOLOGY Finocchiaro, G., Knowles, J. W., Pavlovic, A., Perez, M., Magavern, E., Sinagra, G., Haddad, F., Ashley, E. A. 2014; 113 (2): 361-367


    Hypertrophic cardiomyopathy (HC) is a disease that mainly affects the left ventricle (LV), however recent studies have suggested that it can also be associated with right ventricular (RV) dysfunction. The objective of this study was to determine the prevalence of RV dysfunction in patients with HC and its relation with LV function and outcome. A total of 324 consecutive patients with HC who received care at Stanford Hospital from 1999 to 2012 were included in the study. A group of 99 prospectively recruited age- and gender-matched healthy volunteers were used as controls. RV function was quantified using the RV fractional area change, tricuspid annular plane systolic excursion (TAPSE), and RV myocardial performance index (RVMPI). Compared with the controls, the patients with HC had a higher RVMPI (0.51 ± 0.18 vs 0.25 ± 0.06, p <0.001) and lower TAPSE (20 ± 3 vs 24 ± 4, p <0.001). RV dysfunction based on an RVMPI >0.4 and TAPSE <16 mm was found in 71% and 11% of the HC and control groups, respectively. Worst LV function and greater pulmonary pressures were independent correlates of RV dysfunction. At an average follow-up of 3.7 ± 2.3 years, 17 patients had died and 4 had undergone heart transplantation. LV ejection fraction <50% and TAPSE <16 mm were independent correlates of outcome (hazard ratio 3.98, 95% confidence interval 1.22 to 13.04, p = 0.02; and hazard ratio 3.66, 95% confidence interval 1.38 to 9.69, p = 0.009, respectively). In conclusion, RV dysfunction based on the RVMPI is common in patients with HC and more frequently observed in patients with LV dysfunction and pulmonary hypertension. RV dysfunction based on the TAPSE was independently associated with an increased likelihood of death or transplantation.

    View details for DOI 10.1016/j.amjcaid.2013.09.045

    View details for Web of Science ID 000330253900027

  • Use of Medicare data to identify coronary heart disease outcomes in the Women's Health Initiative. Circulation. Cardiovascular quality and outcomes Hlatky, M. A., Ray, R. M., Burwen, D. R., Margolis, K. L., Johnson, K. C., Kucharska-Newton, A., Manson, J. E., Robinson, J. G., Safford, M. M., Allison, M., Assimes, T. L., Bavry, A. A., Berger, J., Cooper-DeHoff, R. M., Heckbert, S. R., Li, W., Liu, S., Martin, L. W., Perez, M. V., Tindle, H. A., Winkelmayer, W. C., Stefanick, M. L. 2014; 7 (1): 157-162


    . Unique identifier: NCT00000611.

    View details for DOI 10.1161/CIRCOUTCOMES.113.000373

    View details for PubMedID 24399330

  • Evidence of Heterogeneity by Race/Ethnicity in Genetic Determinants of QT Interval. Epidemiology (Cambridge, Mass.) Seyerle, A. A., Young, A. M., Jeff, J. M., Melton, P. E., Jorgensen, N. W., Lin, Y., Carty, C. L., Deelman, E., Heckbert, S. R., Hindorff, L. A., Jackson, R. D., Martin, L. W., Okin, P. M., Perez, M. V., Psaty, B. M., Soliman, E. Z., Whitsel, E. A., North, K. E., Laston, S., Kooperberg, C., Avery, C. L. 2014; 25 (6): 790-8


    QT interval (QT) prolongation is an established risk factor for ventricular tachyarrhythmia and sudden cardiac death. Previous genome-wide association studies in populations of the European descent have identified multiple genetic loci that influence QT, but few have examined these loci in ethnically diverse populations.Here, we examine the direction, magnitude, and precision of effect sizes for 21 previously reported SNPs from 12 QT loci, in populations of European (n = 16,398), African (n = 5,437), American Indian (n = 5,032), Hispanic (n = 1,143), and Asian (n = 932) descent as part of the Population Architecture using Genomics and Epidemiology (PAGE) study. Estimates obtained from linear regression models stratified by race/ethnicity were combined using inverse-variance weighted meta-analysis. Heterogeneity was evaluated using Cochran's Q test.Of 21 SNPs, 7 showed consistent direction of effect across all 5 populations, and an additional 9 had estimated effects that were consistent across 4 populations. Despite consistent direction of effect, 9 of 16 SNPs had evidence (P < 0.05) of heterogeneity by race/ethnicity. For these 9 SNPs, linkage disequilibrium plots often indicated substantial variation in linkage disequilibrium patterns among the various racial/ethnic groups, as well as possible allelic heterogeneity.These results emphasize the importance of analyzing racial/ethnic groups separately in genetic studies. Furthermore, they underscore the possible utility of trans-ethnic studies to pinpoint underlying casual variants influencing heritable traits such as QT.

    View details for DOI 10.1097/EDE.0000000000000168

    View details for PubMedID 25166880

  • Molecular Diagnosis of Long-QT syndrome at 10 Days of Life by Rapid Whole Genome Sequencing. Heart rhythm : the official journal of the Heart Rhythm Society Priest, J. R., Ceresnak, S. R., Dewey, F. E., Malloy-Walton, L. E., Dunn, K., Grove, M. E., Perez, M. V., Maeda, K., Dubin, A. M., Ashley, E. A. 2014


    The advent of clinical next generation sequencing is rapidly changing the landscape of rare disease medicine. Molecular diagnosis of long QT syndrome (LQTS) can impact clinical management, including risk stratification and selection of pharmacotherapy based on the type of ion channel affected, but results from current gene panel testing requires 4 to 16 weeks before return to clinicians.A term female infant presented with 2:1 atrioventricular block and ventricular arrhythmias consistent with perinatal LQTS, requiring aggressive treatment including epicardial pacemaker, and cardioverter-defibrillator implantation and sympathectomy on day of life two. We sought to provide a rapid molecular diagnosis for optimization of treatment strategies.We performed CLIA-certified rapid whole genome sequencing (WGS) with a speed-optimized bioinformatics platform to achieve molecular diagnosis at 10 days of life.We detected a known pathogenic variant in KCNH2 that was demonstrated to be paternally inherited by followup genotyping. The unbiased assessment of the entire catalog of human genes provided by whole genome sequencing revealed a maternally inherited variant of unknown significance in a novel gene.Rapid clinical WGS provides faster and more comprehensive diagnostic information by 10 days of life than standard gene-panel testing. In selected clinical scenarios such as perinatal LQTS, rapid WGS may be able to provide more timely and clinically actionable information than a standard commercial test.

    View details for DOI 10.1016/j.hrthm.2014.06.030

    View details for PubMedID 24973560

  • Electrocardiographic Repolarization-Related Variables as Predictors of Coronary Heart Disease Death in the Women's Health Initiative Study. Journal of the American Heart Association Rautaharju, P. M., Zhang, Z., Vitolins, M., Perez, M., Allison, M. A., Greenland, P., Soliman, E. Z. 2014; 3 (4)


    We evaluated 25 repolarization-related ECG variables for the risk of coronary heart disease (CHD) death in 52 994 postmenopausal women from the Women's Health Initiative study.Hazard ratios from Cox regression were computed for subgroups of women with and without cardiovascular disease (CVD). During the average follow-up of 16.9 years, 941 CHD deaths occurred. Based on electrophysiological considerations, 2 sets of ECG variables with low correlations were considered as candidates for independent predictors of CHD death: Set 1, Ѳ(Tp|Tref), the spatial angle between T peak (Tp) and normal T reference (Tref) vectors; Ѳ(Tinit|Tterm), the angle between the initial and terminal T vectors; STJ depression in V6 and rate-adjusted QTp interval (QTpa); and Set 2, TaVR and TV1 amplitudes, heart rate, and QRS duration. Strong independent predictors with over 2-fold increased risk for CHD death in women with and without CVD were Ѳ(Tp|Tref) >42° from Set 1 and TaVR amplitude >-100 μV from Set 2. The risk for these CHD death predictors remained significant after multivariable adjustment for demographic/clinical factors. Other significant predictors for CHD death in fully adjusted risk models were Ѳ(Tinit|Tterm) >30°, TV1 >175 μV, and QRS duration >100 ms.Ѳ(Tp|Tref) angle and TaVR amplitude are associated with CHD mortality in postmenopausal women. The use of these measures to identify high-risk women for further diagnostic evaluation or more intense preventive intervention warrants further study. Unique identifier: NCT00000611.

    View details for DOI 10.1161/JAHA.114.001005

    View details for PubMedID 25074699

  • Does CHA2DS2-VASc improve stroke risk stratification in postmenopausal women with atrial fibrillation? American journal of medicine Abraham, J. M., Larson, J., Chung, M. K., Curtis, A. B., Lakshminarayan, K., Newman, J. D., Perez, M., Rexrode, K., Shara, N. M., Solomon, A. J., Stefanick, M. L., Torner, J. C., Wilkoff, B. L., Wassertheil-Smoller, S. 2013; 126 (12): 1143 e1-8


    Risk stratification of atrial fibrillation patients with a congestive heart failure (C), hypertension (H), age ≥ 75 (A), diabetes (D), stroke or transient ischemic attack (TIA) (S2) (CHADS2) score of <2 remains imprecise, particularly in women. Our objectives were to validate the CHADS2 and congestive heart failure (C), hypertension (H), age ≥ 75 (A2), diabetes (D), stroke, TIA or prior thromboembolic disease (S2)- vascular disease (V), age 65-74 (A), female gender (S) (CHA2DS2-VASc) stroke risk scores in a healthy cohort of American women with atrial fibrillation and to determine whether CHA2DS2-VASc further risk-stratifies individuals with a CHADS2 score of <2.We identified a cohort of 5981 women with atrial fibrillation not on warfarin at baseline (mean age 65.9 ± 7.2 years) enrolled in the Women's Health Initiative and followed for a median of 11.8 years. Univariate and multivariate proportional hazards analyses were used to examine these 2 risk scores, with main outcome measures being annualized event rates of ischemic stroke or transient ischemic attack stratified by risk score.Annualized stroke/transient ischemic attack rates ranged from 0.36% to 2.43% with increasing CHADS2 score (0-4+) (hazard ratio [HR] 1.57; 95% confidence interval [CI], 1.45-1.71 for each 1-point increase) and 0.20%-2.02% with increasing CHA2DS2-VASc score (1-6+) (HR 1.50; 95% CI, 1.41-1.60 for each 1-point increase). CHA2DS2-VASc had a higher c statistic than CHADS2: 0.67 (95% CI, 0.65-0.69) versus 0.65 (95% CI, 0.62-0.67), P <.01. For CHADS2 scores <2, stroke risk almost doubled with every additional CHA2DS2-VASc point.Although both CHADS2, and CHA2DS2-VASc are predictive of stroke risk in postmenopausal women with atrial fibrillation, CHA2DS2-VASc further risk-stratifies patients with a CHADS2 score <2.

    View details for DOI 10.1016/j.amjmed.2013.05.023

    View details for PubMedID 24139523

  • Variation in Use of Left Ventriculography in the Veterans Affairs Health Care System CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES Heidenreich, P. A., Lin, S., Knowles, J. W., Perez, M., Maddox, T. M., Ho, M. P., Rumsfeld, J. S., Sahay, A., Massie, B. M., Tsai, T. T., Witteles, R. M. 2013; 6 (6): 687-693


    Contrast left ventriculography is a method of measuring left ventricular function usually performed at the discretion of the invasive cardiologist during cardiac catheterization. We sought to determine variation in the use of left ventriculography in the Veterans Affairs (VA) Health Care System.We identified adult patients who underwent cardiac catheterization including coronary angiography between 2000 and 2009 in the VA Health Care System. We determined patient and hospital predictors of the use of left ventriculography as well as the variation in use across VA facilities. Results were validated using data from the VA's Clinical Assessment, Reporting, and Tracking (CART) program. Of 457 170 cardiac catheterization procedures among 336 853 patients, left ventriculography was performed on 263 695 (58%) patients. Use of left ventriculography decreased over time (64% in 2000 to 50% in 2009) and varied markedly across facilities (<1->95% of cardiac catheterizations). Patient factors explained little of the large variation in use between facilities. When the cohort was restricted to those with an echocardiogram in the prior 30 days and no intervening event, left ventriculography was still performed in 50% of cases.There is large variation in the use of left ventriculography across VA facilities that is not explained by patient characteristics.

    View details for DOI 10.1161/CIRCOUTCOMES.113.000199

    View details for Web of Science ID 000330362400017

    View details for PubMedID 24192569

  • Prognostic implications of the J wave ECG patterns JOURNAL OF ELECTROCARDIOLOGY Yong, C. M., Perez, M., Froelicher, V. 2013; 46 (5): 408-410
  • African American race but not genome-wide ancestry is negatively associated with atrial fibrillation among postmenopausal women in the Women's Health Initiative. American heart journal Perez, M. V., Hoffmann, T. J., Tang, H., Thornton, T., Stefanick, M. L., Larson, J. C., Kooperberg, C., Reiner, A. P., Caan, B., Iribarren, C., Risch, N. 2013; 166 (3): 566-572


    Atrial fibrillation (AF) is the most common arrhythmia in women and is associated with higher rates of stroke and death. Rates of AF are lower in African American subjects compared with European Americans, suggesting European ancestry could contribute to AF risk.The Women's Health Initiative (WHI) Observational Study (OS) followed up 93,676 women since the mid 1990s for various cardiovascular outcomes including AF. Multivariate Cox hazard regression analysis was used to measure the association between African American race and incident AF. A total of 8,119 African American women from the WHI randomized clinical trials and OS were genotyped on the Affymetrix Human SNP Array 6.0. Genome-wide ancestry and previously reported single nucleotide polymorphisms associated with AF in European cohorts were tested for association with AF using multivariate logistic regression analyses.Self-reported African American race was associated with lower rates of AF (hazard ratio 0.43, 95% CI 0.32-0.60) in the OS, independent of demographic and clinical risk factors. In the genotyped cohort, there were 558 women with AF. By contrast, genome-wide European ancestry was not associated with AF. None of the single nucleotide polymorphisms previously associated with AF in European populations, including rs2200733, were associated with AF in the WHI African American cohort.African American race is significantly and inversely correlated with AF in postmenopausal women. The etiology of this association remains unclear and may be related to unidentified environmental differences. Larger studies are necessary to identify genetic determinants of AF in African Americans.

    View details for DOI 10.1016/j.ahj.2013.05.024

    View details for PubMedID 24016508

  • J wave patterns and their prognostic value in African Americans JOURNAL OF ELECTROCARDIOLOGY Perez, M. V., Froelicher, V. 2013; 46 (5): 442-445


    Examples of racial differences in physiologic measurements and disease rates abound. What is considered "normal" in one population can be interpreted as a marker of disease in another. Differences in early repolarization patterns, such as J-waves, QRS slurs and ST elevations (STE), on the electrocardiogram (ECG) in those of African compared to non-African descent are prime examples. Here we will review some of the initial observations made in the ECG in Africans, discuss the cohort studies that compare these patterns in African Americans and Caucasians, summarize some of our own observations, and speculate on the nature of these differences.

    View details for DOI 10.1016/j.jelectrocard.2013.06.015

    View details for Web of Science ID 000330268800015

  • Risk factors for atrial fibrillation and their population burden in postmenopausal women: the Women's Health Initiative Observational Study HEART Perez, M. V., Wang, P. J., Larson, J. C., Soliman, E. Z., Limacher, M., Rodriguez, B., Klein, L., Manson, J. E., Martin, L. W., Prineas, R., Connelly, S., Hlatky, M., Wassertheil-Smoller, S., Stefanick, M. L. 2013; 99 (16): 1173-1178


    OBJECTIVE: Atrial fibrillation (AF) is the most common arrhythmia in women. Large studies evaluating key AF risk factors in older women are lacking. We aimed to identify risk factors for AF in postmenopausal women and measure population burden of modifiable risk factors. DESIGN: Prospective observational study. SETTING: The Women's Health Initiative (WHI) Observational Study. PATIENTS: 93 676 postmenopausal women were followed for an average of 9.8 years for cardiovascular outcomes. After exclusion of women with prevalent AF or incomplete data, 8252 of the remaining 81 892 women developed incident AF. MAIN OUTCOME MEASURES: Incident AF was identified by WHI-ascertained hospitalisation records and diagnosis codes from Medicare claims. Multivariate Cox hazard regression analysis identified independent risk factors for incident AF. RESULTS: Age, hypertension, obesity, diabetes, myocardial infarction and heart failure were independently associated with incident AF. Hypertension and overweight status accounted for 28.3% and 12.1%, respectively, of the population attributable risk. Hispanic and African-American participants had lower rates of incident AF (HR 0.58, 95% CI 0.47 to 0.70 and HR 0.59, 95% CI 0.53 to 0.65, respectively) than Caucasians. CONCLUSIONS: Caucasian ethnicity, traditional cardiovascular risk factors and peripheral arterial disease were independently associated with higher rates of incident AF in postmenopausal women. Hypertension and overweight status accounted for a large proportion of population attributable risk. Measuring burden of modifiable AF risk factors in older women may help target interventions.

    View details for DOI 10.1136/heartjnl-2013-303798

    View details for Web of Science ID 000329909700009

  • Different patterns of bundle-branch blocks and the risk of incident heart failure in the Women's Health Initiative (WHI) study. Circulation. Heart failure Zhang, Z., Rautaharju, P. M., Soliman, E. Z., Manson, J. E., Martin, L. W., Perez, M., Vitolins, M., Prineas, R. J. 2013; 6 (4): 655-661


    We evaluated the risk of incident heart failure (HF) associated with bundle-branch blocks (BBBs) in postmenopausal women.Cox's regression was used to evaluate hazard ratios with 95% confidence intervals for HF among 65975 participants of the Women's Health Initiative (WHI) study during an average follow-up of 14 years. BBBs observed in 1676 women at baseline were categorized into left, right, and indetermined-type BBBs (LBBB, RBBB, and intraventricular conduction defect, respectively). Compared with women with no BBB, LBBB, and intraventricular conduction defect were strong predictors of incident HF in multivariable-adjusted risk models (hazard ratio, 3.79; confidence interval, 2.95-4.87 for LBBB and hazard ratio, 3.53; confidence interval, 2.14-5.81 for intraventricular conduction defect). RBBB was not a significant predictor of incident HF in multivariable-adjusted risk model, but the combination of RBBB and left anterior fascicular block was a strong predictor (hazard ratio, 2.96; confidence interval, 1.77-4.93). QRS duration was an independent predictor of incident HF only in LBBB, with more pronounced risk at QRS ≥ 140 ms than at <140 ms. QRS nondipolar voltage (RNDPV) was an independent predictor in both RBBB and LBBB and, in addition, in LBBB, QRS/STT angle and ST J-point depression in aVL were independent predictors.LBBB, intraventricular conduction defect, and RBBB combined with left anterior fascicular block are strong predictors of incident HF in multivariable-adjusted risk models, but RBBB is not a significant predictor. QRS duration ≥ 140 ms may warrant consideration in LBBB as an indication for further diagnostic evaluation for possible therapeutic and preventive action. Clinical Trial Registration- URL: Unique identifier: NCT00000611.

    View details for DOI 10.1161/CIRCHEARTFAILURE.113.000217

    View details for PubMedID 23729198

  • Taming Rare Variation With Known Biology in Long QT Syndrome. Circulation. Cardiovascular genetics Perez, M. V., Ashley, E. A. 2013; 6 (3): 227-229

    View details for DOI 10.1161/CIRCGENETICS.113.000199

    View details for PubMedID 23778589

  • From bedside to bench JOURNAL OF ELECTROCARDIOLOGY Perez, M., Froelicher, V. 2013; 46 (2): 114-115
  • Pacemaker Therapy in Atrial Fibrillation Journal of Cardiology and Vascular Medicine Park, S., Wang, P. J., Zei, P. C., Hsia, H. H., Turakhi, M., Perez, M. V., Al-Ahmad, A. A. 2013; 1: 1-7
  • Effects of Postmenopausal Hormone Therapy on Incident Atrial Fibrillation The Women's Health Initiative Randomized Controlled Trials CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Perez, M. V., Wang, P. J., Larson, J. C., Virnig, B. A., Cochrane, B., Curb, J. D., Klein, L., Manson, J. E., Martin, L. W., Robinson, J., Wassertheil-Smoller, S., Stefanick, M. L. 2012; 5 (6): 1108-1116


    Atrial fibrillation (AF) is less prevalent in women versus men, but associated with higher risks of stroke and death in women. The role hormone therapy plays in AF is not well understood.The Women's Health Initiative randomized postmenopausal women to placebo or conjugated equine estrogens (0.625 mg/d) plus medroxyprogesterone acetate (2.5 mg/d) if they had a uterus (N=16 608) or to conjugated equine estrogens only if they had prior hysterectomy (N=10 739). Incident AF was identified by ECG and diagnosis codes from Medicare claims or hospitalization records. Hazard ratios for incident AF were estimated using Cox proportional hazards regression. After excluding participants with baseline AF, there were 611 incident AF cases over a mean of 5.6 years among 16 128 estrogen plus progestin participants, and 683 cases over a mean of 7.1 years among 10 251 conjugated equine estrogens alone participants. Incident AF was more frequent in the active groups of both trials, reaching statistical significance in the trial of conjugated equine estrogens alone in women with prior hysterectomy (hazard ratio, 1.17; CI, 1.00-1.36; P=0.045) and in the pooled analysis (hazard ratio, 1.12; CI, 1.00-1.24; P=0.05), but not in the estrogen plus progestin trial (hazard ratio, 1.07; CI, 0.91-1.25; P=0.44). These results were only minimally affected by adjustment for incident stroke, coronary heart disease, and heart failure.Incident AF was modestly elevated in hysterectomized women randomized to postmenopausal E-alone, and in the pooled group randomized to E-alone or estrogen plus progestin. The trend in women with intact uterus receiving estrogen plus progestin, considered separately, was not statistically; Identifier: NCT00000611.

    View details for DOI 10.1161/CIRCEP.112.972224

    View details for Web of Science ID 000313586900018

    View details for PubMedID 23169946

  • Semantic Confusion: The Case of Early Repolarization and the J Point AMERICAN JOURNAL OF MEDICINE Perez, M. V., Friday, K., Froelicher, V. 2012; 125 (9): 843-844

    View details for DOI 10.1016/j.amjmed.2011.08.024

    View details for Web of Science ID 000308693000010

    View details for PubMedID 22340816

  • Prognostic Implications of Q Waves and T-Wave Inversion Associated With Early Repolarization MAYO CLINIC PROCEEDINGS Uberoi, A., Sallam, K., Perez, M., Jain, N. A., Ashley, E., Froelicher, V. 2012; 87 (7): 614-619


    To evaluate the prevalence of early polarization (ER) in a stable population and to evaluate the prognostic significance of the association or absence of Q waves or T-wave inversion (TWI).In this retrospective study performed at the university-affiliated Palo Alto Veterans Affairs Health Care Center from March 1, 1987, through December 31, 1999, we evaluated outpatient electrocardiograms. Vital status and cause of death were determined in all patients, with a mean ± SD follow-up of 7.6±3.8 years.Of the 29,281 patients, 87% were men and 13% were African American. Inferior or lateral ER was present in 664 patients (2.3%): in inferior leads in 185 (0.6%), in lateral leads in 479 (1.6%) , and in both inferior and lateral leads in 163 (0.6%). Only when Q waves or TWI accompanied ER was there an increased risk of cardiovascular death (Cox proportional hazards regression model, 5.0; 95% confidence interval, 3.4-7.2; P<.001).Common patterns of ER without concomitant Q waves or TWI are not associated with increased risk of cardiovascular death; however, when either occurs with ER, there is a hazard ratio of 5.0. These findings confirm that ER is a benign entity; however, the presence of Q waves or TWI with ER is predictive of increased cardiovascular death.

    View details for DOI 10.1016/j.mayocp.2012.04.009

    View details for Web of Science ID 000306872800003

    View details for PubMedID 22766081

  • Use and overuse of left ventriculography AMERICAN HEART JOURNAL Witteles, R. M., Knowles, J. W., Perez, M., Morris, W. M., Spettell, C. M., Brennan, T. A., Heidenreich, P. A. 2012; 163 (4): 617-?


    Left ventriculography provided the first imaging of left ventricular function and was historically performed as part of coronary angiography despite a small but significant risk of complications. Because modern noninvasive imaging techniques are more accurate and carry smaller risks, the routine use of left ventriculography is of questionable utility. We sought to analyze the frequency that left ventriculography was performed during coronary angiography in patients with and without a recent alternative assessment of left ventricular function.We performed a retrospective analysis of insurance claims data from the Aetna health care benefits database including all adults who underwent coronary angiography in 2007. The primary outcome was the concomitant use of left ventriculography during coronary angiography.Of 96,235 patients who underwent coronary angiography, left ventriculography was performed in 78,705 (81.8%). Use of left ventriculography was high in all subgroups, with greatest use in younger patients, those with a diagnosis of coronary disease, and those in the Southern United States. In the population who had undergone a very recent ejection fraction assessment by another modality (within 30 days) and who had had no intervening diagnosis of new heart failure, myocardial infarction, hypotension, or shock (37,149 patients), left ventriculography was performed in 32,798 patients (88%)-a rate higher than in the overall cohort.Left ventriculography was performed in most coronary angiography cases and often when an alternative imaging modality had been recently completed. New clinical practice guidelines should be considered to decrease the overuse of this invasive test.

    View details for DOI 10.1016/j.ahj.2011.12.018

    View details for Web of Science ID 000303106800023

    View details for PubMedID 22520528

  • The prognostic value of early repolarization with ST-segment elevation in African Americans HEART RHYTHM Perez, M. V., Uberoi, A., Jain, N. A., Ashley, E., Turakhia, M. P., Froelicher, V. 2012; 9 (4): 558-565


    Increased prevalence of classic early repolarization, defined as ST-segment elevation (STE) in the absence of acute myocardial injury, in African Americans is well established. The prognostic value of this pattern in different ethnicities remains controversial.Measure association between early repolarization and cardiovascular mortality in African Americans.The resting electrocardiograms of 45,829 patients were evaluated at the Palo Alto Veterans Affairs Hospital. Subjects with inpatient status or electrocardiographic evidence of acute myocardial infarction were excluded, leaving 29,281 subjects. ST-segment elevation, defined as an elevation of >0.1 mV at the end of the QRS, was electronically flagged and visually adjudicated by 3 observers blinded to outcomes. An association between ethnicity and early repolarization was measured by using multivariate logistic regression. We analyzed associations between early repolarization and cardiovascular mortality by using the Cox proportional hazards regression analysis.Subjects were 13% women and 13.3% African Americans, with an average age of 55 years and followed for an average of 7.6 years, resulting in 1995 cardiovascular deaths. There were 479 subjects with lateral STE and 185 with inferior STE. After adjustment for age, sex, heart rate, and coronary artery disease, African American ethnicity was associated with lateral or inferior STE (odds ratio 3.1; P = .0001). While lateral or inferior STE in non-African Americans was independently associated with cardiovascular death (hazard ratio 1.6; P = .02), it was not associated with cardiovascular death in African Americans (hazard ratio 0.75; P = .50).Although early repolarization is more prevalent in African Americans, it is not predictive of cardiovascular death in this population and may represent a distinct electrophysiologic phenomenon.

    View details for DOI 10.1016/j.hrthm.2011.11.020

    View details for Web of Science ID 000302258100020

    View details for PubMedID 22094072

  • Catheter ablation of atrial fibrillation: state-of-the-art techniques and future perspectives JOURNAL OF CARDIOVASCULAR MEDICINE Santangeli, P., Di Biase, L., Burkhardt, D. J., Horton, R., Sanchez, J., Bai, R., Pump, A., Perez, M., Wang, P. J., Natale, A., Al-Ahmad, A. 2012; 13 (2): 108-124


    The impact of atrial fibrillation on the healthcare systems of Western countries is overwhelming, due to its independent association with death, systemic thromboembolism, impaired quality of life and hospitalizations. Catheter ablation is the only treatment thus far demonstrated capable of achieving cure in a substantial proportion of patients. Pulmonary vein antrum isolation (PVAI) is the cornerstone of current atrial fibrillation ablation techniques, with the greatest efficacy as a stand-alone procedure in patients with paroxysmal atrial fibrillation. Use of general anesthesia, open-irrigated ablation catheters and maintenance of periprocedural therapeutic warfarin has been demonstrated to increase the safety and effectiveness of PVAI. In patients with paroxysmal atrial fibrillation, the systematic addition of superior vena cava isolation increases the long-term freedom from atrial fibrillation recurrence. A more extensive ablation approach extending to the entire left atrial posterior wall and to complex fractionated electrograms (CFAEs) is warranted in nonparoxysmal atrial fibrillation patients, in whom nonpulmonary vein trigger sites are frequently identified. Up to one-third of these patients experiencing atrial fibrillation recurrence after ablation have evidence of triggers from the left atrial appendage. Isolation of this structure is the best treatment strategy to improve the long-term success rate. In recent years, in addition to the development of ablation techniques to increase the success rate, outcomes of atrial fibrillation treatment trials have been reconsidered. In particular, reduction of hospitalization, stroke and mortality, as well as economic factors, have all been considered relevant to evaluate the effectiveness of atrial fibrillation treatment. Large ongoing trials are specifically evaluating the impact of atrial fibrillation ablation on these outcomes. This article will summarize the state-of-the art techniques for atrial fibrillation ablation, and will discuss the contribution of ongoing studies to the future of atrial fibrillation ablation.

    View details for DOI 10.2459/JCM.0b013e32834f2371

    View details for Web of Science ID 000299652200004

    View details for PubMedID 22193837

  • Early Repolarization in an Ambulatory Clinical Population CIRCULATION Uberoi, A., Jain, N. A., Perez, M., Weinkopff, A., Ashley, E., Hadley, D., Turakhia, M. P., Froelicher, V. 2011; 124 (20): 2208-2214


    The significance of early repolarization, particularly regarding the morphology of the R-wave downslope, has come under question.We evaluated 29 281 resting ambulatory ECGs from the VA Palo Alto Health Care System. With PR interval as the isoelectric line and amplitude criteria ?0.1 mV, ST-segment elevation is defined at the end of the QRS, J wave as an upward deflection, and slur as a conduction delay on the QRS downstroke. Associations of ST-segment elevation patterns, J waves, and slurs with cardiovascular mortality were analyzed with Cox analysis. With a median follow-up of 7.6 years, there were 1995 cardiac deaths. Of 29 281 subjects, 87% were male (55±14 years) and 13% were female (56±17 years); 13% were black, 6% were Hispanic, and 81% were white or other. Six hundred sixty-four (2.3%) had inferior or lateral ST-segment elevation: 185 (0.6%) in inferior leads and 479 (1.6%) in lateral leads, 163 (0.6%) in both, and 0.4% had global elevation. A total of 4041 ECGs were analyzed with enhanced display, and 583 (14%) had J waves or slurring, which were more prevalent in those with than in those without ST-segment elevation (61% versus 13%; P<0.001). ST-segment elevation occurred more in those with than in those without J waves or slurs (12% versus 1.3%; P<0.001). Except when involving only inferior leads, all components of early repolarization were more common in young individuals, male subjects, blacks, and those with bradycardia. All patterns and components of early repolarization were associated with decreased cardiovascular mortality, but this was not significant after adjustment for age.We found no significant association between any components of early repolarization and cardiac mortality.

    View details for DOI 10.1161/CIRCULATIONAHA.111.047191

    View details for Web of Science ID 000297060700013

    View details for PubMedID 21986288

  • The Impact of ST Elevation on Athletic Screening CLINICAL JOURNAL OF SPORT MEDICINE Leo, T., Uberoi, A., Jain, N. A., Garza, D., Chowdhury, S., Freeman, J. V., Perez, M., Ashley, E., Froelicher, V. 2011; 21 (5): 433-440


    To demonstrate the prevalence and patterns of ST elevation (STE) in ambulatory individuals and athletes and compare the clinical outcomes.Retrospective cohort study. ST elevation was measured by computer algorithm and defined as ?0.1 mV at the end of the QRS complex. Elevation was confirmed, and J waves and slurring were coded visually.Veterans Affairs Palo Alto Health Care System and Stanford University varsity athlete screening evaluation.Overall, 45 829 electrocardiograms (ECGs) were obtained from the clinical patient cohort and 658 ECGs from athletes. We excluded inpatients and those with ECG abnormalities, leaving 20 901 outpatients and 641 athletes.Electrocardiogram evaluation and follow-up for vital status.All-cause and cardiovascular mortality and cardiac events.ST elevation in the anterior and lateral leads was more prevalent in men and in African Americans and inversely related to age and resting heart rate. Athletes had a higher prevalence of early repolarization even when matched for age and gender with nonathletes. ST elevation greater than 0.2 mV (2 mm) was very unusual. ST elevation was not associated with cardiac death in the clinical population or with cardiac events or abnormal test results in the athletes.Early repolarization is not associated with cardiac death and has patterns that help distinguish it from STE associated with cardiac conditions, such as myocardial ischemia or injury, pericarditis, and the Brugada syndrome.

    View details for DOI 10.1097/JSM.0B013E31822CF105

    View details for Web of Science ID 000294485000009

    View details for PubMedID 21892017

  • Interpretation of the Electrocardiogram of Young Athletes CIRCULATION Uberoi, A., Stein, R., Perez, M. V., Freeman, J., Wheeler, M., Dewey, F., Peidro, R., Hadley, D., Drezner, J., Sharma, S., Pelliccia, A., Corrado, D., Niebauer, J., Estes, M., Ashley, E., Froelicher, V. 2011; 124 (6): 746-757
  • Gene Coexpression Network Topology of Cardiac Development, Hypertrophy, and Failure CIRCULATION-CARDIOVASCULAR GENETICS Dewey, F. E., Perez, M. V., Wheeler, M. T., Watt, C., Spin, J., Langfelder, P., Horvath, S., Hannenhalli, S., Cappola, T. P., Ashley, E. A. 2011; 4 (1): 26-U129


    Network analysis techniques allow a more accurate reflection of underlying systems biology to be realized than traditional unidimensional molecular biology approaches. Using gene coexpression network analysis, we define the gene expression network topology of cardiac hypertrophy and failure and the extent of recapitulation of fetal gene expression programs in failing and hypertrophied adult myocardium.We assembled all myocardial transcript data in the Gene Expression Omnibus (n=1617). Because hierarchical analysis revealed species had primacy over disease clustering, we focused this analysis on the most complete (murine) dataset (n=478). Using gene coexpression network analysis, we derived functional modules, regulatory mediators, and higher-order topological relationships between genes and identified 50 gene coexpression modules in developing myocardium that were not present in normal adult tissue. We found that known gene expression markers of myocardial adaptation were members of upregulated modules but not hub genes. We identified ZIC2 as a novel transcription factor associated with coexpression modules common to developing and failing myocardium. Of 50 fetal gene coexpression modules, 3 (6%) were reproduced in hypertrophied myocardium and 7 (14%) were reproduced in failing myocardium. One fetal module was common to both failing and hypertrophied myocardium.Network modeling allows systems analysis of cardiovascular development and disease. Although we did not find evidence for a global coordinated program of fetal gene expression in adult myocardial adaptation, our analysis revealed specific gene expression modules active during both development and disease and specific candidates for their regulation.

    View details for DOI 10.1161/CIRCGENETICS.110.941757

    View details for Web of Science ID 000287353200014

    View details for PubMedID 21127201

  • Personalized Medicine and Cardiovascular Disease: From Genome to Bedside Current Cardiovascular Risk Reports S. Pan, F. E. Dewey, M. V. Perez, J. W. Knowles, R. Chen, A. J. Butte, E. A. Ashley 2011; 5: 542-551
  • Cost-Effectiveness of Genetic Testing in Family Members of Patients With Long-QT Syndrome CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES Perez, M. V., Kumarasamy, N. A., Owens, D. K., Wang, P. J., Hlatky, M. A. 2011; 4 (1): 76-84


    Family members of patients with established long-QT syndrome (LQTS) often lack definitive clinical findings, yet may have inherited an LQTS mutation and be at risk of sudden death. Genetic testing can identify mutations in 75% of patients with LQTS, but genetic testing of family members remains controversial.We used a Markov model to assess the cost-effectiveness of 3 strategies for treating an asymptomatic 10-year-old, first-degree relative of a patient with clinically evident LQTS. In the genetic testing strategy, relatives undergo genetic testing only for the mutation identified in the index patient, and relatives who test positive for the mutation are treated with ?-blockers. This strategy was compared with (1) empirical treatment of relatives with ?-blockers and (2) watchful waiting, with treatment only after development of symptoms. The genetic testing strategy resulted in better survival and quality-adjusted life years at higher cost, with a cost-effectiveness ratio of $67 400 per quality-adjusted life year gained compared with watchful waiting. The cost-effectiveness of the genetic testing strategy improved to less than $50 000 per quality-adjusted life year gained when applied selectively either to (1) relatives with higher clinical suspicion of LQTS (pretest probability 65% to 81%), or to (2) families with a higher than average risk of sudden death, or to (3) larger families (2 or more first-degree relatives tested).Genetic testing of young first-degree relatives of patients with definite LQTS is moderately expensive, but can reach acceptable thresholds of cost-effectiveness when applied to selected patients.

    View details for DOI 10.1161/CIRCOUTCOMES.110.957365

    View details for Web of Science ID 000286311700014

    View details for PubMedID 21139095

  • Inappropriate pacing in a patient with managed ventricular pacing: What is the cause? HEART RHYTHM Perez, M. V., Al-Ahmad, A. A., Wang, P. J., Turakhia, M. P. 2010; 7 (9): 1336-1337


    A case of inappropriate atrial pacing in a patient with a pacemaker programmed with Managed Ventricular Pacing (MVP) mode, a proprietary algorithm in Medtronic devices, is presented. The patient was an 84-year-old woman who presented in sinus rhythm with complete atrioventricular block. A dual-chamber pacemaker was implanted and programmed to an MVP pacing mode. After the implant, the patient developed a relatively slow atrial tachyarrhythmia with 2:1 atrioventricular block and inappropriate atrial pacing, followed by a delay in tracking of the atrial tachyarrhythmia. The mechanisms for these behaviors are described.

    View details for DOI 10.1016/j.hrthm.2010.04.028

    View details for Web of Science ID 000281444100033

    View details for PubMedID 20435165

  • Addition of the Electrocardiogram to the Preparticipation Examination of College Athletes CLINICAL JOURNAL OF SPORT MEDICINE Le, V., Wheeler, M. T., Mandic, S., Dewey, F., Fonda, H., Perez, M., Sungar, G., Garza, D., Ashley, E. A., Matheson, G., Froelicher, V. 2010; 20 (2): 98-105


    Although the use of standardized cardiovascular (CV) system-focused history and physical examination is recommended for the preparticipation examination (PPE) of athletes, the addition of the electrocardiogram (ECG) has been controversial. Because the impact of ECG screening on college athletes has rarely been reported, we analyzed the findings of adding the ECG to the PPE of Stanford athletes.For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.Although the use of standardized CV-focused history and physical examination are recommended for the PPE of athletes, the addition of the ECG has been controversial. Because the feasibility and outcomes of ECG screening on college athletes have rarely been reported, we present findings derived from the addition of the ECG to the PPE of Stanford athletes. For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.Six hundred fifty-eight recordings were obtained (54% men, 10% African-American, mean age 20 years) representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete right bundle branch block (RBBB) (13%), right axis deviation (RAD) (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for left ventricular hypertrophy (LVH) were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7%, and only 5 men had abnormal Q-waves. Sixty-three athletes (10%) were judged to have distinctly abnormal ECG findings possibly associated with conditions including hypertrophic cardiomyopathy or arrhythmogenic right ventricular dysplasia/cardiomyopathy. These athletes were offered further testing but this was not mandated according to the research protocol.Six hundred fifty-three recordings were obtained (54% men, 7% African American, mean age 20 years), representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete RBBB (13%), RAD (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for LVH were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7% and only 5 men had abnormal Q-waves. Sixty-five athletes (10%) were judged to have distinctly abnormal ECG findings suggestive of arrhythmogenic right ventricular dysplasia, hypertrophic cardiomyopathy, and/or biventricular hypertrophy. These athletes will be submitted to further testing.Mass ECG screening is achievable within the collegiate setting by using volunteers when the appropriate equipment is available. However, the rate of secondary testing suggests the need for an evaluation of cost-effectiveness for mass screening and the development of new athlete-specific ECG interpretation algorithms.

    View details for DOI 10.1097/JSM.0b013e3181d44705

    View details for Web of Science ID 000275481500005

    View details for PubMedID 20215891

  • Adding an Electrocardiogram to the Pre-participation Examination in Competitive Athletes: A Systematic Review CURRENT PROBLEMS IN CARDIOLOGY Perez, M., Fonda, H., Le, V., Mitiku, T., Ray, J., Freeman, J. V., Ashley, E., Froelicher, V. F. 2009; 34 (12): 586-662


    No matter how rare, the death of young athletes is a tragedy. Can it be prevented? The European experience suggests that adding the electrocardiogram (ECG) to the standard medical and family history and physical examination can decrease cardiac deaths by 90%. However, there has not been a randomized trial to demonstrate such a reduction. While there are obvious differences between the European and American experiences with athletes including very differing causes of athletic deaths, some would highlight the European emphasis on public welfare vs the protection of personal rights in the USA. Even the authors of this systematic review have differing interpretation of the data: some of us view screening as a hopeless battle against Bayes, while others feel that the ECG can save lives. What we all agree on is that the USA should implement the American Heart Association 12-point screening recommendations and that, before ECG screening is mandated, we need to gather more data and optimize ECG criteria for screening young athletes.

    View details for DOI 10.1016/j.cpcardiol.2009.08.002

    View details for Web of Science ID 000271915700002

    View details for PubMedID 19887232

  • Electrocardiographic predictors of atrial fibrillation AMERICAN HEART JOURNAL Perez, M. V., Dewey, F. E., Marcus, R., Ashley, E. A., Al-Ahmad, A. A., Wang, P. J., Froelicher, V. F. 2009; 158 (4): 622-628


    Atrial fibrillation (AF) is the most prevalent arrhythmia in the United States and accounts for more than 750,000 strokes per year. Noninvasive predictors of AF may help identify patients at risk of developing AF. Our objective was to identify the electrocardiographic characteristics associated with onset of AF.This was a retrospective cohort analysis of 42,751 patients with electrocardiograms (ECGs) ordered by physician's discretion and analyzed using a computerized system. The population was followed for detection of AF on subsequent ECGs. Cox proportional hazard regression analysis was performed to test the association between these ECG characteristics and development of AF.For a mean follow-up of 5.3 years, 1,050 (2.4%) patients were found to have AF on subsequent ECG recordings. Several ECG characteristics, such as P-wave dispersion (the difference between the widest and narrowest P waves), premature atrial contractions, and an abnormal P axis, were predictive of AF with hazard ratio of approximately 2 after correcting for age and sex. P-wave index, the SD of P-wave duration across all leads, was one of the strongest predictors of AF with a concordance index of 0.62 and a hazard ratio of 2.7 (95% CI 2.1-3.3) for a P-wave index >35. These were among the several independently predictive markers identified on multivariate analysis.Several ECG markers are independently predictive of future onset of AF. The P index, a measurement of disorganized atrial depolarization, is one of the strongest predictors of AF. The ECG contains valuable prognostic information that can identify patients at risk of AF.

    View details for DOI 10.1016/j.ahj.2009.08.002

    View details for Web of Science ID 000270706100020

    View details for PubMedID 19781423

  • Mechanisms of exercise intolerance in patients with hypertrophic cardiomyopathy AMERICAN HEART JOURNAL Le, V., Perez, M. V., Wheeler, M. T., Myers, J., Schnittger, I., Ashley, E. A. 2009; 158 (3): E27-E34


    To determine the relation between echocardiogram findings and exercise capacity in hypertrophic cardiomyopathy (HCM).Sixty-three patients (48 +/- 15 years) were referred for cardiopulmonary testing and exercise echocardiography. They were classified by morphology: proximal (n = 11), reverse curvature (n = 32), apical (n = 7), and concentric HCM (n = 13). There were more women in proximal and reverse curvature groups. Proximal HCM patients were older. Maximal left ventricular thickness was highest in reverse curvature group. At peak exercise, concentric HCM achieved the lowest percent predicted maximal Vo2. Excluding apical group, no significant differences in gradient were noted between groups. Overall, no statistically significant correlation was found between peak Vo2, wall thickness, and gradient. Significant correlations were noted between peak Vo2 and indexed left atrial (LA) volume (r = -0.52), lateral E' (r = 0.50), and lateral E/E' ratio (r = -0.46). A multivariate model including age, lateral E', indexed LA volume, and mitral A wave explained 46% of the variance in peak Vo2 (P = .01).Lateral E' and indexed LA volume are negatively correlated with functional capacity. Although patients with concentric morphology achieved the lowest peak Vo2, wall thickness and gradient did not predict exercise capacity.

    View details for DOI 10.1016/j.ahj.2009.06.006

    View details for Web of Science ID 000269641200027

    View details for PubMedID 19699847

  • Statin Use and Ventricular Arrhythmias During Clinical Treadmill Testing JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY Dewey, F. E., Perez, M., Hadley, D., Freeman, J. V., Wang, P., Ashley, E. A., Myers, J., Froelicher, V. F. 2009; 20 (2): 193-199


    Premature ventricular complexes (PVCs) during exercise are associated with adverse prognosis, particularly in patients with intermediate treadmill test findings. Statin use reduces the incidence of resting ventricular arrhythmias in patients with coronary artery disease; however, the relationship between statin use and exercise-induced ventricular arrhythmias has not been investigated.We evaluated the association between statin use and PVCs in 1,847 heart-failure-free patients (mean age 58, 95% male) undergoing clinical exercise treadmill testing between 1997 and 2004 in the VA Palo Alto Health Care System. PVCs were quantified in beats per minute and frequent PVCs were defined as PVC rates greater than the median value (0.43 and 0.60 PVCs per minute for exercise and recovery, respectively). Propensity-adjusted logistic regression was used to evaluate the odds of developing PVCs during exercise and recovery periods associated with statin use. There were 431 subjects who developed frequent PVCs during exercise and 284 subjects had frequent recovery PVCs. After propensity score adjustment, subjects treated with statins (n = 145) had 42% lower odds of developing frequent PVCs during exercise (odds ratio [OR] 0.58, 95% confidence interval [CI] 0.37-0.93) and 44% lower odds of developing frequent PVCs during recovery (OR 0.56, 95% CI 0.30-0.94). These effects were not modified by age, prior coronary disease, hypercholesterolemia, exercise-induced angina, or exercise capacity.Statin use was associated with reduced odds of frequent PVCs during and after clinical exercise testing in a manner independent of associations with coronary disease or ischemia in our study population.

    View details for DOI 10.1111/j.1540-8167.2008.01284.x

    View details for Web of Science ID 000262889000012

    View details for PubMedID 18775041

  • Added Value of a Resting ECG Neural Network That Predicts Cardiovascular Mortality ANNALS OF NONINVASIVE ELECTROCARDIOLOGY Perez, M. V., Dewey, F. E., Tan, S. Y., Myers, J., Froelicher, V. F. 2009; 14 (1): 26-34


    The resting 12-lead electrocardiogram (ECG) remains the most commonly used test in evaluating patients with suspected cardiovascular disease. Prognostic values of individual findings on the ECG have been reported but may be of limited use.The characteristics of 45,855 ECGs ordered by physician's discretion were first recorded and analyzed using a computerized system. Ninety percent of these ECGs were used to train an artifical neural network (ANN) to predict cardiovascular mortality (CVM) based on 132 ECG and four demographic characteristics. The ANN generated a Resting ECG Neural Network (RENN) score that was then tested in the remaining ECGs. The RENN score was finally assessed in a cohort of 2189 patients who underwent exercise treadmill testing and were followed for CVM.The RENN score was able to better predict CVM compared to individual ECG markers or a traditional Cox regression model in the testing cohort. Over a mean of 8.6 years, there were 156 cardiovascular deaths in the treadmill cohort. Among the patients who were classified as intermediate risk by Duke Treadmill Scoring (DTS), the third tertile of the RENN score demonstrated an adjusted Cox hazard ratio of 5.4 (95% CI 2.0-15.2) compared to the first RENN tertile. The 10-year CVM was 2.8%, 8.6% and 22% in the first, second and third RENN tertiles, respectively.An ANN that uses the resting ECG and demographic variables to predict CVM was created. The RENN score can further risk stratify patients deemed at moderate risk on exercise treadmill testing.

    View details for DOI 10.1111/j.1542-474X.2008.00270.x

    View details for Web of Science ID 000262508800005

    View details for PubMedID 19149790

  • Isolated Disease of the Proximal Left Anterior Descending Artery Comparing the Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Surgery JACC-CARDIOVASCULAR INTERVENTIONS Kapoor, J. R., Gienger, A. L., Ardehali, R., Varghese, R., Perez, M. V., Sundaram, V., McDonald, K. M., Owens, D. K., Hlatky, M. A., Bravata, D. M. 2008; 1 (5): 483-491


    This study sought to systematically compare the effectiveness of percutaneous coronary intervention and coronary artery bypass surgery in patients with single-vessel disease of the proximal left anterior descending (LAD) coronary artery.It is uncertain whether percutaneous coronary interventions (PCI) or coronary artery bypass grafting (CABG) surgery provides better clinical outcomes among patients with single-vessel disease of the proximal LAD.We searched relevant databases (MEDLINE, EMBASE, and Cochrane from 1966 to 2006) to identify randomized controlled trials that compared outcomes for patients with single-vessel proximal LAD assigned to either PCI or CABG.We identified 9 randomized controlled trials that enrolled a total of 1,210 patients (633 received PCI and 577 received CABG). There were no differences in survival at 30 days, 1 year, or 5 years, nor were there differences in the rates of procedural strokes or myocardial infarctions, whereas the rate of repeat revascularization was significantly less after CABG than after PCI (at 1 year: 7.3% vs. 19.5%; at 5 years: 7.3% vs. 33.5%). Angina relief was significantly greater after CABG than after PCI (at 1 year: 95.5% vs. 84.6%; at 5 years: 84.2% vs. 75.6%). Patients undergoing CABG spent 3.2 more days in the hospital than those receiving PCI (95% confidence interval: 2.3 to 4.1 days, p < 0.0001), required more transfusions, and were more likely to have arrhythmias immediately post-procedure.In patients with single-vessel, proximal LAD disease, survival was similar in CABG-assigned and PCI-assigned patients; CABG was significantly more effective in relieving angina and led to fewer repeat revascularizations.

    View details for DOI 10.1016/j.jcin.2008.07.001

    View details for Web of Science ID 000207586300004

    View details for PubMedID 19463349

  • Genetics of Arrhythmia: Disease Pathways Beyond Ion Channels JOURNAL OF CARDIOVASCULAR TRANSLATIONAL RESEARCH Perez, M. V., Wheeler, M., Ho, M., Pavlovic, A., Wang, P., Ashley, E. A. 2008; 1 (2): 155-165


    Diseases of the electrical conduction system that lead to irregularities in cardiac rhythm can have morbid and often lethal clinical outcomes. Linkage analysis has been the principal tool used to discover the genetic mutations responsible for Mendelian arrhythmic disease. Although the majority of arrhythmias can be accounted for by mutations in genes encoding ion channels, linkage analysis has also uncovered the role of other gene families such as those encoding members of the desmosome. With a list of candidates in mind, mutational analysis has helped confirm the suspicion that proteins found in caveolae or gap junctions also play a role in arrhythmogenesis. Atrial fibrillation and sudden cardiac death are relatively common arrhythmias that may be caused by multiple factors including common genetic variants. Genome-wide association studies are already revealing the important and poorly understood role of intergenic regions in atrial fibrillation. Despite the great advancements that have been made in our understanding of the genetics of these diseases, we are still far from able to routinely use genomic data to make clinical management decisions. There remain several hurdles in the study of genetics of arrhythmia, including the costs of genotyping, the need to find large affected families for linkage analysis, or to recruit large numbers of patients for genome-wide studies. Novel techniques that incorporate epigenetic information, such as known gene-gene interactions, biologic pathways, and experimental gene expression, will need to be developed to better interpret the large amount of genetic data that can now be generated. The study of arrhythmia genetics will continue to elucidate the pathophysiology of disease, help identify novel therapies, and ultimately allow us to deliver the individualized medical therapy that has long been anticipated.

    View details for DOI 10.1007/s12265-008-9030-4

    View details for Web of Science ID 000207734800012

    View details for PubMedID 20559910

  • Systematic review: The comparative effectiveness of percutaneous coronary interventions and coronary artery bypass graft surgery ANNALS OF INTERNAL MEDICINE Bravata, D. M., Gienger, A. L., McDonald, K. M., Sundaram, V., Perez, M. V., Varghese, R., Kapoor, J. R., Ardehali, R., Owens, D. K., Hlatky, M. A. 2007; 147 (10): 703-U139


    The comparative effectiveness of coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) for patients in whom both procedures are feasible remains poorly understood.To compare the effectiveness of PCI and CABG in patients for whom coronary revascularization is clinically indicated.MEDLINE, EMBASE, and Cochrane databases (1966-2006); conference proceedings; and bibliographies of retrieved articles.Randomized, controlled trials (RCTs) reported in any language that compared clinical outcomes of PCI with those of CABG, and selected observational studies.Information was extracted on study design, sample characteristics, interventions, and clinical outcomes.The authors identified 23 RCTs in which 5019 patients were randomly assigned to PCI and 4944 patients were randomly assigned to CABG. The difference in survival after PCI or CABG was less than 1% over 10 years of follow-up. Survival did not differ between PCI and CABG for patients with diabetes in the 6 trials that reported on this subgroup. Procedure-related strokes were more common after CABG than after PCI (1.2% vs. 0.6%; risk difference, 0.6%; P = 0.002). Angina relief was greater after CABG than after PCI, with risk differences ranging from 5% to 8% at 1 to 5 years (P < 0.001). The absolute rates of angina relief at 5 years were 79% after PCI and 84% after CABG. Repeated revascularization was more common after PCI than after CABG (risk difference, 24% at 1 year and 33% at 5 years; P < 0.001); the absolute rates at 5 years were 46.1% after balloon angioplasty, 40.1% after PCI with stents, and 9.8% after CABG. In the observational studies, the CABG-PCI hazard ratio for death favored PCI among patients with the least severe disease and CABG among those with the most severe disease.The RCTs were conducted in leading centers in selected patients. The authors could not assess whether comparative outcomes vary according to clinical factors, such as extent of coronary disease, ejection fraction, or previous procedures. Only 1 small trial used drug-eluting stents.Compared with PCI, CABG was more effective in relieving angina and led to fewer repeated revascularizations but had a higher risk for procedural stroke. Survival to 10 years was similar for both procedures.

    View details for Web of Science ID 000251259500005

    View details for PubMedID 17938385

  • Prognostic value of the computerized ECG in Hispanics CLINICAL CARDIOLOGY Perez, M. V., Yaw, T. S., Myers, J., Froelicher, V. F. 2007; 30 (4): 189-194


    The prevalence and prognostic values of electrocardiogram (ECG) abnormalities in Hispanics have not been compared to other ethnicities in a large population. Despite a worse cardiovascular risk profile, the prevalence of cardiovascular disease is lower in Hispanics compared to non-Hispanics.We hypothesized that ECG abnormalities were less common in Hispanics and were not as strongly associated with cardiovascular mortality.45,563 ECGs ordered for usual clinical indications in a Veteran's hospital were available for analysis. 1,392 patients who died within one week of the ECG were excluded. Demographic characteristics were recorded and the population was followed for an average of 7.5 years using the California Death Index. The presence of baseline ECG characteristics were recorded and analyzed using the GE/Marquette computerized ECG system. Age, sex and heart rate adjusted Cox hazard ratio analyses were performed.Being Hispanic was associated with lower cardiovascular death, with a hazard ratio (HR) of 0.76 (95% CI 0.65-0.89). Findings such as atrial fibrillation, presence of Q-waves, left ventricular hypertrophy (LVH), upright T-waves in aortic valve replacement (aVR) and cardiac Infarction Injury Scores > 6 were significantly less prevalent in Hispanics than in non-Hispanics. These findings were similarly associated with increased cardiovascular mortality in both groups, each with a HR of approximately 2.The lower prevalence of ECG characteristics associated with coronary heart disease, atrial fibrillation and left ventricular hypertrophy support prior observations that cardiovascular disease is less prevalent in the Hispanic population. These findings, however, are similarly associated with increased mortality compared to non-Hispanics.

    View details for DOI 10.1002/clc.20053

    View details for Web of Science ID 000245794400008

    View details for PubMedID 17443659

  • Giant coronary aneurysms in heart transplantation: an unusual presentation of cardiac allograft vasculopathy JOURNAL OF HEART AND LUNG TRANSPLANTATION Haddad, F., Perez, M., Fleischmann, D., Valantine, H., Hunt, S. A. 2006; 25 (11): 1367-1370


    Cardiac allograft vasculopathy is a leading cause of death during long-term follow-up of heart transplant recipients. We report 2 cases of cardiac allograft vasculopathy associated with giant coronary aneurysms. To our knowledge, these are the first reported cases of spontaneous giant coronary aneurysms in heart transplant recipients.

    View details for DOI 10.1016/j.healun.2006.07.006

    View details for Web of Science ID 000242222100015

    View details for PubMedID 17097503

  • p300/MDM2 complexes participate in MDM2-mediated p53 degradation MOLECULAR CELL Grossman, S. R., Perez, M., Kung, A. L., Joseph, M., Mansur, C., Xiao, Z. X., Kumar, S., Howley, P. M., Livingston, D. M. 1998; 2 (4): 405-415


    Control of p53 turnover is critical to p53 function. E1A binding to p300/CBP translates into enhanced p53 stability, implying that these coactivator proteins normally operate in p53 turnover control. In this regard, the p300 C/H1 region serves as a specific in vivo binding site for both p53 and MDM2, a naturally occurring p53 destabilizer. Moreover, most of the endogenous MDM2 is bound to p300, and genetic analysis implies that specific interactions of p53 and MDM2 with p300 C/H1 are important steps in the MDM2-directed turnover of p53. A specific role for p300 in endogenous p53 degradation is underscored by the p53-stabilizing effect of overproducing the p300 C/H1 domain. Taken together, the data indicate that specific interactions between p300/CBP C/H1, p53, and MDM2 are intimately involved in the MDM2-mediated control of p53 abundance.

    View details for Web of Science ID 000076678900001

    View details for PubMedID 9809062

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