Source:Basavarajaiah S, Boraita A, Whyte G, et al. Ethnic differences in left ventricular remodeling in highly-trained athletes: relevance to differentiating physiologic left ventricular hypertrophy from hypertrophic cardiomyopathy.
J Am Coll Cardiol.
–2262; doi:10.1016/j.jacc.2007.12.061

The purpose of this British study was to evaluate ethnic differences in cardiovascular adaptation to intense physical activity.

Between 20032007, 300 asymptomatic elite black male athletes in the UK underwent a 12-lead electrocardiogram (ECG) and two-dimensional echocardiography during their peak competitive season. Control participants consisted of 150 black and 150 white sedentary males, and 300 white male elite athletes participating in sporting events similar to the elite black athletes. An elite athlete was defined as an individual who underwent organized training and participated in a team or individual sport at a national level.

The term “black” was used to denote individuals of African or Afro-Caribbean descent. The ethnicity of study participants was based on information provided on health questionnaires. Athletes from a variety of sporting disciplines (soccer, boxing, basketball, track sprinting, rugby, tennis) participated in this study and trained on average 14 hours per week. Left ventricular hypertrophy (LVH) was defined as a left ventricular (LV) end-diastolic wall thickness greater than 12 mm. Study participants with documented LVH underwent exercise stress-testing and 48-hour Holter monitoring to further delineate physiologic LVH from hypertrophic cardiomyopathy (HCM).

The mean age of the black athletes was 20.5 years (range 1435 years) and the mean age of white athletes was 20.2 (range 1435). Black athletes showed a significantly larger end-diastolic LV wall thickness and LV mass compared to white athletes. Significantly more black athletes (18%) demonstrated LVH than white athletes (4%). Three percent (n=9) of the black athletes had substantial LVH with wall thickness measurements ≥ 15 mm. None of the sedentary control participants had evidence of LVH.

Black athletes with LVH displayed an enlarged LV cavity and normal diastolic function. Black athletes with LVH had a higher prevalence of ECG abnormalities, including voltage criteria for LVH and repolarization changes (ST-segment elevation, T-wave inversion). Deep T-wave inversions were present in four of the nine black athletes with substantial LVH whereas none of the white athletes with LVH demonstrated deep T-wave abnormalities. Exercise stress testing was normal in all athletes with LVH and none of the athletes in this study were ultimately diagnosed with HCM.

The authors conclude that upper limits of normal for end diastolic LV wall thickness should be adjusted in certain elite athletes. In the absence of cardiac symptoms or a family history of HCM, an end-diastolic LV wall thickness of ≥12 mm in elite black athletes may represent physiologic LVH when the LV cavity is enlarged and diastolic function is normal.

Dr. Bernhardt has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.

Intensive training or participation in physical activity results in increased size of the LV.1,3 A LV...

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