Abstract 3268: Ethnic Differences in the 12 Lead -EKG - Relevance to the Cardiovascular Evaluation for Hypertrophic Cardiomyopathy in Athletes

Abstract

Introduction Cardiac adaptation to intense physical exercise is associated with physiological increases in cardiac dimensions that are reflected on the EKG. The EKG changes in Caucasian athletes (WA) are established, however, there is a paucity of data in black athletes (BA) who constitute an increasing proportion of elite athletes in Western countries. We sought to identify differences (if any) in EKG characteristics between BA and WA participating in similar sporting disciplines. Methods Between 2007– 8, 222 nationally ranked male BA aged 14 –35 and 496 WA of similar age, size and range of sporting disciplines underwent a EKG and standard 2-D echocardiography. All athletes with a left ventricular wall thickness > 12mm and deep T wave inversion (> −0.2 mV) underwent Holter monitor, exercise stress test, and cardiac MRI to exclude phenotypic features of hypertrophic cardiomyopathy (HCM). Results Black athletes had a greater prevalence of voltage criteria for left ventricular hypertrophy (LVH) (57% vs 42%; p < 0.005), ST segment elevation (76% vs 33%; p < 0.001) and T wave inversions (25% vs 4%; p < 0.001) compared with WA. ST segment elevation in all athletes was confined to the anterior precordial leads but 50% BA exhibited a unique convex ST segment elevation pattern that was absent in WA. There was no correlation between T wave inversions and LVH at echocardiography or cardiac MRI. Indeed none of the BA with T wave inversions displayed any phenotypic features of HCM. Conclusion Black athletes exhibit different adaptive responses to exercise than WA. Deep T wave inversions and convex ST segment elevation are common in BA, with or without LVH and may overlap with HCM. These results have significant implications during pre-participation screening. There is the potential risk of generating a false positive diagnosis of HCM and lead to unnecessary exclusion from competitive sport, if data derived from WA, used to identify an abnormal EKG, is incorrectly extrapolated to BA.