The prevalence, distribution, and clinical outcomes of electrocardiographic repolarization patterns in male athletes of African/Afro-Caribbean origin

AIMS

Athletic training in male black athletes (BAs) is associated with marked ECG repolarization changes that overlap with hypertrophic cardiomyopathy (HCM). Differentiating between the two entities is prudent since BAs exhibit a higher prevalence of exercise-related sudden death from HCM compared with white athletes (WAs).

METHODS AND RESULTS

Between 1996 and 2010, 904 BAs underwent serial cardiac evaluations including ECG and echocardiography. Athletes exhibiting T-wave inversions were investigated further for HCM. Results were compared with 1819 WAs, 119 black controls (BCs), and 52 black HCM patients. Athletes were followed up for 69.7 ± 29.6 months. T-wave inversions were present in 82.7% HCM patients, 22.8% BAs, 10.1% BCs, and 3.7% WAs. In athletes, the major determinant of T-wave inversions was black ethnicity. T-wave inversions in BAs (12.7%) were predominantly confined to contiguous anterior leads (V1-V4). Only 4.1% of BAs exhibited T-wave inversions in the lateral leads. In contrast, both BCs and HCM patients exhibited lower prevalence of T-wave inversions in leads V1-V4 (4.2 and 3.8%, respectively) with most T-wave inversions in HCM patients (76.9%) involving the lateral leads. During follow-up one BA survived cardiac arrest and two athletes (one BA, one WA) were diagnosed with HCM. All three exhibited T-wave inversions in the lateral leads.

CONCLUSIONS

T-wave inversions in leads V1-V4 appear to represent an ethnic variant of 'athlete's heart'. Conversely, T-wave inversions in the lateral leads may represent the initial expression of underlying cardiomyopathy and merit further evaluation and regular surveillance.

Ethnic differences in left ventricular remodeling in highly-trained athletes relevance to differentiating physiologic left ventricular hypertrophy from hypertrophic cardiomyopathy

OBJECTIVES

The purpose of this study was to evaluate ethnic differences in left ventricular (LV) remodeling between highly-trained athletes of African/Afro-Caribbean (black) and Caucasian (white) athletes.

BACKGROUND

The upper limits of left ventricular hypertrophy (LVH) are established in white athletes and aid the differentiation of physiologic LVH from hypertrophic cardiomyopathy (HCM). However, there are few data regarding LV remodeling in black athletes, in whom deaths from HCM are more prevalent.

METHODS

Between 2003 and 2007, 300 nationally ranked black male athletes (mean age 20.5 years) underwent 12-lead electrocardiogram and 2-dimensional echocardiography. The results were compared with 150 black and white sedentary individuals and 300 highly-trained white male athletes matched for age, size, and sport.

RESULTS

Black athletes exhibited greater LV wall thickness and cavity size compared with sedentary black and white individuals. Black athletes had greater LV wall thickness compared with white athletes (11.3 +/- 1.6 mm vs. 10 +/- 1.5 mm; p < 0.001). In absolute terms, 54 black athletes (18%) had LV wall thickness >12 mm compared with 12 white athletes (4%), and 3% of black athletes exhibited LV wall thickness >/=15 mm compared with none of the white athletes. Black athletes with LVH displayed an enlarged LV cavity and normal diastolic function.

CONCLUSIONS

Black athletes develop a greater magnitude of LVH compared with white athletes; therefore, extrapolation of conclusions derived from white athletes has the potential of generating false-positive diagnoses of HCM in black athletes.