Purpose: Although marked repolarisation abnormalities (MRAs) are considered innocuous in trained athletes, their functional significance awaits clarification. The aim of this study was to further evaluate the pathophysiological implications of such MRAs.
Methods: We compared left ventricular (LV) functional response to exhausting exercise in 39 male athletes with (n=22) or without (n=17) MRAs and with no structural cardiac abnormalities, by means of a portable radionuclide monitoring system (Vest, Capintec, Inc., Ramsey, NJ). MRAs were defined by the presence of negative T waves > or =2 mm in three or more rest ECG leads. The Vest data were averaged for 30 s and analysed at baseline and at different heart rate (HR) values (50%, 75%, 85%, 95% and 100% of peak HR), as well as at 2, 5 and 10 min of recovery.
Results: There were no significant differences in the effect of exhausting exercise between athletes with and athletes without MRAs. However, there was a significant difference in the trend in end-diastolic volume (EDV) during exercise depending upon the group of athletes considered (p=0.05). EDV differed significantly between the two groups of athletes at peak HR (p=0.031). EDV in athletes with MRAs was lower than that in athletes without MRAs (102%+/-7% vs 107%+/-8%, p=0.034).
Conclusion: EDV is decreased at peak HR in athletes with MRAs. Such high HR values are infrequently achieved or maintained during sporting activities; therefore, in the absence of structural heart disease, MRAs should not preclude physical training and competitive availability.