Abbas Zaidi

Comparison of Electrocardiographic Criteria for the Detection of Cardiac Abnormalities in Elite Black and White Athletes

Background— Recent efforts have focused on improving the specificity of the European Society of Cardiology (ESC) criteria for ECG interpretation in athletes. These criteria are derived predominantly from white athletes (WAs) and do not account for the effect of Afro-Caribbean ethnicity or novel research questioning the relevance of several isolated ECG patterns. We assessed the impact of the ESC criteria, the newly published Seattle criteria, and a group of proposed refined criteria in a large cohort of black athletes (BAs) and WAs. Methods and Results— Between 2000 and 2012, 1208 BAs were evaluated with history, examination, 12-lead ECG, and further investigations as appropriate. ECGs were retrospectively analyzed according to the ESC recommendations, Seattle criteria, and proposed refined criteria which exclude several specific ECG patterns when present in isolation. All 3 criteria were also applied to 4297 WAs and 103 young athletes with hypertrophic cardiomyopathy. The ESC recommendations raised suspicion of a cardiac abnormality in 40.4% of BAs and 16.2% of WAs. The Seattle criteria reduced abnormal ECGs to 18.4% in BAs and 7.1% in WAs. The refined criteria further reduced abnormal ECGs to 11.5% in BAs and 5.3% in WAs. All 3 criteria identified 98.1% of athletes with hypertrophic cardiomyopathy. Compared with ESC recommendations, the refined criteria improved specificity from 40.3% to 84.2% in BAs and from 73.8% to 94.1% in WAs without compromising the sensitivity of the ECG in detecting pathology. Conclusion— Refinement of current ECG screening criteria has the potential to significantly reduce the burden of false-positive ECGs in athletes, particularly BAs.

Comparison of ECG Criteria for the Detection of Cardiac Abnormalities in Elite Black and White Athletes

Background— Recent efforts have focused on improving the specificity of the European Society of Cardiology (ESC) criteria for ECG interpretation in athletes. These criteria are derived predominantly from white athletes (WAs) and do not account for the effect of Afro-Caribbean ethnicity or novel research questioning the relevance of several isolated ECG patterns. We assessed the impact of the ESC criteria, the newly published Seattle criteria, and a group of proposed refined criteria in a large cohort of black athletes (BAs) and WAs. Methods and Results— Between 2000 and 2012, 1208 BAs were evaluated with history, examination, 12-lead ECG, and further investigations as appropriate. ECGs were retrospectively analyzed according to the ESC recommendations, Seattle criteria, and proposed refined criteria which exclude several specific ECG patterns when present in isolation. All 3 criteria were also applied to 4297 WAs and 103 young athletes with hypertrophic cardiomyopathy. The ESC recommendations raised suspicion of a cardiac abnormality in 40.4% of BAs and 16.2% of WAs. The Seattle criteria reduced abnormal ECGs to 18.4% in BAs and 7.1% in WAs. The refined criteria further reduced abnormal ECGs to 11.5% in BAs and 5.3% in WAs. All 3 criteria identified 98.1% of athletes with hypertrophic cardiomyopathy. Compared with ESC recommendations, the refined criteria improved specificity from 40.3% to 84.2% in BAs and from 73.8% to 94.1% in WAs without compromising the sensitivity of the ECG in detecting pathology. Conclusion— Refinement of current ECG screening criteria has the potential to significantly reduce the burden of false-positive ECGs in athletes, particularly BAs.

Increased left ventricular trabeculation in highly trained athletes: do we need more stringent criteria for the diagnosis of left ventricular non-compaction in athletes?

Objective To investigate the prevalence and significance of increased left ventricular (LV) trabeculation in highly trained athletes. Design Cross sectional echocardiographic study. Setting Sports cardiology institutions in the UK and France. Subjects 1146 athletes aged 14–35 years (63.3% male), participating in 27 sporting disciplines, and 415 healthy controls of similar age. The results of athletes fulfilling conventional criteria for LV non-compaction (LVNC) were compared with 75 patients with LVNC. Main outcome measure Number of athletes with increased LV trabeculation and the number fulfilling criteria for LVNC. Results Athletes displayed a higher prevalence of increased LV trabeculation compared with controls (18.3% vs 7.0%; p≤0.0001) and 8.1% athletes fulfilled conventional criteria for LVNC. Increased LV trabeculation were more common in athletes of African/Afro-Caribbean origin. A small proportion of athletes (n=10; 0.9%) revealed reduced systolic function and marked repolarisation changes in association with echocardiographic criteria for LVNC raising the possibility of an underlying cardiomyopathy. Follow-up during the ensuing 48.6±14.6 months did not reveal adverse events. Conclusions A high proportion of young athletes exhibit conventional criteria for LVNC highlighting the non-specific nature of current diagnostic criteria if applied to elite athletic populations. Further assessment of such athletes should be confined to the small minority that demonstrate low indices of systolic function and marked repolarisation changes.

Reversible De Novo Left Ventricular Trabeculations in Pregnant Women Implications for the Diagnosis of Left Ventricular Noncompaction in Low-Risk Populations

Background— Patients with heart failure and chronic anemia frequently demonstrate left ventricular (LV) trabeculations, which may be compatible with the diagnosis of LV noncompaction. We used the pregnancy model, which is characterized by a reversible increase in cardiac preload and other changes in cardiac function, to assess the development of de novo LV trabeculations in women with morphologically normal hearts. Methods and Results— One hundred two primigravida pregnant women were evaluated longitudinally with a series of echocardiograms in the first trimester, in the third trimester, and postpartum. Echocardiograms were analyzed according to established guidelines. Increased LV trabeculations and the presence of LV noncompaction were based on established criteria. Pregnancy was associated with an increased heart rate, stroke volume, and cardiac output, as well as increased LV volume and mass. During pregnancy, 26 women (25.4%) developed increased trabeculations. Eight women showed sufficient trabeculations to fulfill criteria for LV noncompaction. During the postpartum follow-up period of 24±3 months, 19 women (73%) demonstrated complete resolution of trabeculations, and 5 showed a marked reduction in the trabeculated layer. Conclusions— Pregnancy induces de novo LV trabeculations in a significant proportion of women. The results suggest that LV trabeculations occur in response to increased LV loading conditions or other physiological responses to pregnancy and are not specific for LV noncompaction. These factors should be considered in the assessment of individuals with LV trabeculations outside the context of symptoms of heart failure or familial cardiomyopathy.Background— Patients with heart failure and chronic anemia frequently demonstrate left ventricular (LV) trabeculations, which may be compatible with the diagnosis of LV noncompaction. We used the pregnancy model, which is characterized by a reversible increase in cardiac preload and other changes in cardiac function, to assess the development of de novo LV trabeculations in women with morphologically normal hearts. Methods and Results— One hundred two primigravida pregnant women were evaluated longitudinally with a series of echocardiograms in the first trimester, in the third trimester, and postpartum. Echocardiograms were analyzed according to established guidelines. Increased LV trabeculations and the presence of LV noncompaction were based on established criteria. Pregnancy was associated with an increased heart rate, stroke volume, and cardiac output, as well as increased LV volume and mass. During pregnancy, 26 women (25.4%) developed increased trabeculations. Eight women showed sufficient trabeculations to fulfill criteria for LV noncompaction. During the postpartum follow-up period of 24±3 months, 19 women (73%) demonstrated complete resolution of trabeculations, and 5 showed a marked reduction in the trabeculated layer. Conclusions— Pregnancy induces de novo LV trabeculations in a significant proportion of women. The results suggest that LV trabeculations occur in response to increased LV loading conditions or other physiological responses to pregnancy and are not specific for LV noncompaction. These factors should be considered in the assessment of individuals with LV trabeculations outside the context of symptoms of heart failure or familial cardiomyopathy. # CLINICAL PERSPECTIVE {#article-title-24}

Physiological Right Ventricular Adaptation in Elite Athletes of African and Afro-Caribbean Origin

Background— Regular, intensive exercise results in physiological biventricular cardiac adaptation. Ethnicity is an established determinant of left ventricular remodeling; black athletes (BAs) exhibit more profound LV hypertrophy than white athletes (WAs). Right ventricular (RV) remodeling has not been characterized in BAs, although the issue is pertinent because BAs commonly exhibit ECG anomalies that resemble arrhythmogenic RV cardiomyopathy. Methods and Results— Between 2006 and 2012, 300 consecutive BAs (n=243 males) from 25 sporting disciplines were evaluated by use of ECG and echocardiography. Results were compared with 375 WAs and 153 sedentary control subjects (n=69 blacks). There were no ethnic differences between RV parameters in control subjects. Both BAs and WAs exhibited greater RV dimensions than control subjects. RV dimensions were marginally smaller in BAs than in WAs (proximal outflow tract, 30.9±5.5 versus 32.8±5.3 mm, P<0.001; longitudinal dimension, 86.6±9.5 versus 89.8±9.6 mm, P<0.001), although only 2.3% of variation was attributable to ethnicity. RV enlargement compatible with diagnostic criteria for arrhythmogenic RV cardiomyopathy was frequently observed (proximal outflow tract ≥32 mm; 45.0% of BAs, 58.5% of WAs). Anterior T-wave inversion was present in 14.3% of BAs versus 3.7% of WAs (P<0.001). Marked RV enlargement with concomitant anterior T-wave inversion was observed in 3.0% of BAs versus 0.3% of WAs (P=0.005). Further investigation did not diagnose arrhythmogenic RV cardiomyopathy in any athlete. Conclusions— Physiological RV enlargement is commonly observed in both black and white athletes. The impact of ethnicity is minimal, which obviates the need for race-specific RV reference values. However, in the context of frequent ECG repolarization anomalies in BAs, the potential for erroneous diagnosis of arrhythmogenic RV cardiomyopathy is considerably greater in this ethnic group.

Should axis deviation or atrial enlargement be categorised as abnormal in young athletes? The athlete's electrocardiogram: time for re-appraisal of markers of pathology

AIMS The 2010 European Society of Cardiology (ESC) guidelines for electrocardiogram (ECG) interpretation in athletes are associated with a relatively high false positive rate and warrant modification to improve the specificity without compromising sensitivity. The aim of this study was to investigate whether non-specific anomalies such as axis deviation and atrial enlargement in isolation require further assessment in highly trained young athletes. METHOD AND RESULTS Between 2003 and 2011, 2533 athletes aged 14-35 years were investigated with 12-lead ECG and echocardiography. Electrocardiograms were analysed for non-training-related (Group 2) changes according to the 2010 ESC guidelines. Results were compared with 9997 asymptomatic controls. Of the 2533 athletes, 329 (13%) showed Group 2 ECG changes. Isolated axis deviation and isolated atrial enlargement comprised 42.6% of all Group 2 changes. Athletes revealed a slightly higher prevalence of these anomalies compared with controls (5.5 vs. 4.4%; P = 0.023). Echocardiographic evaluation of athletes and controls with isolated axis deviation or atrial enlargement (n = 579) failed to identify any major structural or functional abnormalities. Exclusion of axis deviation or atrial enlargement reduced the false positive rate from 13 to 7.5% and improved specificity from 90 to 94% with a minimal reduction in sensitivity (91-89.5%). CONCLUSION Isolated axis deviation and atrial enlargement comprise a high burden of Group 2 changes in athletes and do not predict underlying structural cardiac disease. Exclusion of these anomalies from current ESC guidelines would improve specificity and cost-effectiveness of pre-participation screening with ECG.

Clinical significance of electrocardiographic right ventricular hypertrophy in athletes: comparison with arrhythmogenic right ventricular cardiomyopathy and pulmonary hypertension

AIMS Pre-participation cardiovascular screening of young athletes may prevent sports-related sudden cardiac deaths. Recognition of physiological electrocardiography (ECG) changes in healthy athletes has improved the specificity of screening while maintaining sensitivity for disease. The study objective was to determine the clinical significance of electrocardiographic right ventricular hypertrophy (RVH) in athletes. METHODS AND RESULTS Between 2010 and 2012, 868 subjects aged 14-35 years (68.8% male) were assessed using ECG and echocardiography (athletes; n = 627, sedentary controls; n = 241). Results were compared against patients with established right ventricular (RV) pathology (arrhythmogenic right ventricular cardiomyopathy, n = 68; pulmonary hypertension, n = 30). Sokolow-Lyon RVH (R[V1]+S[V5orV6] > 1.05 mV) was more prevalent in athletes than controls (11.8 vs. 6.2%, P = 0.017), although RV wall thickness (RVWT) was similar (4.0 ± 1.0 vs. 3.9 ± 0.9 mm, P = 0.18). Athletes exhibiting electrocardiographic RVH were predominantly male (95.9%), and demonstrated similar RV dimensions and function to athletes with normal electrocardiograms (RVWT; 4.0 ± 1.1 vs. 4.0 ± 0.9 mm, P = 0.95, RV basal dimension; 42.7 ± 5.2 vs. 42.1 ± 5.9 mm, P = 0.43, RV fractional area change; 40.6 ± 7.6 vs. 42.2 ± 8.1%, P = 0.14). Sensitivity and specificity of Sokolow-Lyon RVH for echocardiographic RVH (>5 mm) were 14.3 and 88.2%, respectively. Further evaluation including cardiac magnetic resonance imaging did not diagnose right ventricular pathology in any athlete. None of the cardiomyopathic or pulmonary hypertensive patients exhibited voltage RVH without additional ECG abnormalities. CONCLUSION Electrocardiographic voltage criteria for RVH are frequently fulfilled in healthy athletes without underlying RV pathology, and should not prompt further evaluation if observed in isolation. Recognition of this phenomenon should reduce the burden of investigations after pre-participation ECG screening without compromising sensitivity for disease.

Clinical Differentiation Between Physiological Remodeling and Arrhythmogenic Right Ventricular Cardiomyopathy in Athletes With Marked Electrocardiographic Repolarization Anomalies.

BACKGROUND Physiological cardiac adaptation to regular exercise, including biventricular dilation and T-wave inversion (TWI), may create diagnostic overlap with arrhythmogenic right ventricular cardiomyopathy (ARVC). OBJECTIVES The goal of this study was to assess the accuracy of diagnostic criteria for ARVC when applied to athletes exhibiting electrocardiographic TWI and to identify discriminators between physiology and disease. METHODS The study population consisted of athletes with TWI (n = 45), athletes without TWI (n = 35), and ARVC patients (n = 35). Subjects underwent electrocardiography (ECG), signal-averaged electrocardiography (SAECG), echocardiography, cardiac magnetic resonance imaging (CMRI), Holter monitoring, and exercise testing. RESULTS There were no electrical, structural, or functional cardiac differences between athletes exhibiting TWI and athletes without TWI. When athletes were compared with ARVC patients, markers of physiological remodeling included early repolarization, biphasic TWI, voltage criteria for right ventricular (RV) or left ventricular hypertrophy, and symmetrical cardiac enlargement. Indicators of RV pathology included the following: syncope; Q waves or precordial QRS amplitudes <1.8 mV; 3 abnormal SAECG parameters; delayed gadolinium enhancement, RV ejection fraction ≤45%, or wall motion abnormalities at CMRI; >1,000 ventricular extrasystoles (or >500 non-RV outflow tract) per 24 h; and symptoms, ventricular tachyarrhythmias, or attenuated blood pressure response during exercise. Nonspecific parameters included the following: prolonged QRS terminal activation; ≤2 abnormal SAECG parameters; RV dilation without wall motion abnormalities; RV outflow tract ectopy; and exercise-induced T-wave pseudonormalization. CONCLUSIONS TWI and balanced biventricular dilation are likely to represent benign manifestations of training in asymptomatic athletes without relevant family history. Diagnostic criteria for ARVC are nonspecific in such individuals. Comprehensive testing using widely available techniques can effectively differentiate borderline cases.

Cardiac adaptation to exercise in adolescent athletes of African ethnicity: an emergent elite athletic population

Background/aims Adult black athletes (BA) exhibit left ventricular hypertrophy (LVH) on echocardiography and marked ECG repolarisation changes resembling those observed in hypertrophic cardiomyopathy (HCM). Limited data are available for adolescent BA, the group most vulnerable to exercise-related sudden cardiac death. Methods Between 1996 and 2011, 245 male and 84 female adolescent BA from a wide variety of sporting disciplines underwent cardiac evaluation including ECG and echocardiography. Athletes exhibiting T-wave inversions and/or echocardiographic LVH were investigated further for quiescent cardiomyopathies. Results were compared with 903 adolescent white athletes (WA) and 134 adolescent sedentary black controls (BC). Results LVH on echocardiography was present in 7% of BA compared to only 0.6% of WA and none of the BC. In the very young (<16 years), 5.5% of BA, but none of the WA, demonstrated LVH. Within the BA group, LVH was more prevalent in men compared to women (9% vs 1.2%, p=0.012). T-wave inversions were present in 22.8% BA, 4.5% WA and 13.4% BC. T-wave inversions in BA occurred with similar frequency in men and women and were predominantly confined to leads V1–V4. T-wave inversions in the lateral leads, commonly associated with cardiomyopathies, were present in 2.4% of BA. On a further evaluation and mean follow-up of 8.3 years, none of the athletes exhibited HCM. Conclusions Athletic training has a pronounced effect on adolescent BA. Black athletes as young as 14 years of age may exhibit left ventricular wall thicknesses of 15 mm and marked repolarisation changes resembling HCM. Male and female BA demonstrate a high prevalence of T-wave inversions.

Exercise-induced arrhythmogenic right ventricular cardiomyopathy: fact or fallacy?

This editorial refers to ‘Exercise-induced right ventricular dysfunction and structural remodelling in endurance athletes’, by A. La Gerche et al. , doi:10.1093/eurheartj/ehr397 The cardiovascular benefits of regular exercise are established; individuals exercising regularly have an average life expectancy of 7 years longer than their sedentary counterparts.1 Indeed exercise is regarded as one of the most potent and cost-effective treatments dispensed by health professionals in the management of an adverse risk profile for generalized atherosclerosis. Such benefits are achievable with relatively modest doses of exercise amounting to 6–10 METS (metabolic equivalents) per day2 and are devoid of the side effects associated with usual drug therapy. Analogously to pharmacological treatments, it is recognized that exercise exhibits an inverted J-shaped dose–benefit response with respect to musculoskeletal injuries; however, the concept that intensive exercise may exert a detrimental effect in individuals with normal hearts is rarely entertained and has never been investigated in large cohorts. The majority of highly trained athletes exercise intensively for several hours per day, resulting in workloads of 200–300 METS per week which is 5–10 times greater than the exercise recommendations for preventing coronary atherosclerosis. Cross-sectional studies in athletes demonstrate modest increases in cardiac size with preserved indices of systolic and diastolic function and high scores during objective assessment of functional capacity.3 Adverse cardiac events in athletes are also low and most frequently confined to those harbouring hereditary or congenital cardiac abnormalities.4 These facts support the widely held notion that exercise is beneficial irrespective of the dose and, contrary to the haemodynamic circumstances associated with cardiac pathologies, the paradigm has evolved that ‘the athletes big heart is beautiful’. The past three decades have witnessed somewhat of a paradox consisting of an increase in obesity and cardiac morbidity due to lack of habitual exercise as well as a …