Cardiac troponin T and I, electrocardiographic wall motion analyses, and ejection fractions in athletes participating in the Hawaii Ironman Triathlon

Cardiac troponin T (cTnT) and troponin l (cTnl) are highly sensitive and sp ecific for detecting myocardial damage even in the presence of skeletal mus cle injury. In this study, we assessed whether ultraendurance exercise indu ced cardiomyocyte injury using plasma cTnT and cTnl measurements, quantitat ive echocardiographic wall-motion analysis, and ejection fraction measureme nt in athletes who participated in the Hawaii Ironman Triathlon, Twenty-thr ee athletes (11 men) who completed the triathlon (3.9 km swim, 180.2 km bik e, and 42.2 km run) participated in this study. Blood samples were obtained 2 days before and immediately after the triathlon for the determination of cTnT (Enzymun, Roche Diagnostics) and cTnl (Dade Behring) concentrations. Quantitative echocardiographic wall motion analysis and ejection fraction w ere obtained on 12 of the 23 participants before and immediately after the race, No subject had detectable cTnT or cTnl or abnormal echo score before the race. Following the race, 2 subjects (0%) had marked increases in both cTnT (0.15 and 0.33 mu g/L) and cTnl (2.09 and 4.44 mu g/L). Four additiona l subjects (17%) had moderate increases in cTnT (0.04 to 0.05 mu g/L) but n o detectable cTnl, Race time correlated inversely with cTnT (r = -0.65, p < 0.01). Mean change in the number of abnormal echo segments after the race was 6.5 in those with a marked increase in cTnT and cTnl, 2.3 in those with a moderate increase in cTnT, and 1.7 in those with no increase. Ejection f raction decreased by an average of 24% after the race (p < 0.002), Thus, ul traendurance exercise may cause myocardial damage as indicated by biochemic al cardiac-specific markers and echocardiography, The cellular nature of th is damage and whether it is transient or permanent is unclear at present. ( C) 1999 by Excerpta Medica, Inc.