Postexercise Left Ventricular Function and cTnT in Recreational Marathon Runners KEITH GEORGE 1 , GREGORY WHYTE 2 , CLAIRE STEPHENSON 3 , ROBERT SHAVE 4 , ELLEN DAWSON 3 , BEN EDWARDS 1 , DAVID GAZE 5 , and PAUL COLLINSON 5 1 Research Institute for Sport and Exercise Science, Henry Cotton Campus, Liverpool John Moores University, Liverpool, UNITED KINGDOM; 2 Olympic Medical Institute, Northwick Park Hospital, Harrow, Middlesex, UNITED KINGDOM; 3 Centre for Clinical and Biophysical Research in Human Movement, Manchester Metropolitan University, Alsager, UNITED KINGDOM; 4 Department of Sport Sciences, Brunel University, Uxbridge, Middlesex, UNITED KINGDOM; and 5 Department of Chemical Pathology, St. George’s Hospital Medical School, Tooting, London, UNITED KINGDOM ABSTRACT GEORGE, K., G. WHYTE, C. STEPHENSON, R. SHAVE, E. DAWSON, B. EDWARDS, D. GAZE, and P. COLLINSON. Postexercise Left Ventricular Function and cTnT in Recreational Marathon Runners. Med. Sci. Sports Exerc., Vol. 36, No. 10, pp. 1709 –1715, 2004. Purpose: To assess the impact of prolonged exercise on left ventricular (LV) function and the appearance of cardiac troponin T (cTnT) in older and recreational athletes. Methods: Heart rate (HR), blood pressures, and cTnT were recorded in 35 subjects (age range 22–57 yr, finishing time 157–341 min) pre- and postrace. Echocardiograms (N = 26) assessed stroke volume (SV), ejection fraction (EF), sBP/LV end-systolic volume (sBP/ESV), diastolic filling (E:A ratio) as well as preload (LV internal dimension at end-diastole [LVIDd]) and afterload (LV wall stress). HR and core temperature were recorded in-event. Prepost changes in LV function were analyzed by repeated measures t-test. Delta scores for LV function and cTnT data were correlated with each other, age, finishing time, alterations in loading, and in-event data. Results: SV was significantly decreased postrace (109  31 vs 85  25 mL, P  0.05) likely due to a significant decrease in LVIDd (5.3  0.4 vs 4.9  0.5 cm, P  0.05; r = 0.80, P  0.05). LV wall stress was unchanged postrace (90  25 vs 89  27 g·cm -2 , P  0.05). EF (70  12 vs.70  10%, P  0.05) and sBP/ESV (3.7  2.9 vs 4.0  2.0, P  0.05) did not change prepost race and were not related to age or finishing time (P  0.05). E:A ratio was significantly reduced postrace (1.73  0.38 vs 1.41  0.25, P  0.05) and could not be explained by an increased HR (56  9 vs 84  10, P  0.05; r = 0.08, P  0.05), a reduced LVIDd (r = 0.11, P  0.05), age, finishing time, or in-event data. Postrace 26/33 subjects presented cTnT values in the range 0.024 – 0.080 g·L -1 that were not related to changes in LV function, loading, age, finishing time, or in-event data. Conclusion: No evidence of load-independent depression in LV systolic function was reported. Changes in cTnT and E:A were not related, and their etiology is uncertain. Key Words: EJECTION FRACTION, DIASTOLIC FUNCTION, CARDIAC FATIGUE, CARDIAC TROPONIN T A lthough not entirely unanimous (8), a growing body of evidence would suggest that prolonged exercise may induce a transient reduction in left ventricular (LV) function (fatigue) as well as promote the appearance of cardiac-specific troponins (cTnT and cTnI), normally indic- ative of myocyte necrosis (5,19). To date, most of the available literature has studied young, well-trained athletes competing in ultra-endurance events such as an Ironman Triathlon (6,24,31) or exercise of even longer duration (1,4,20). Less information is available for prolonged exercise in a broader range of subject ages and training levels. With the increasing participation of recre- ational athletes in activities such as marathon running, and the uncertain clinical significance of depressed LV function and cTnT appearance (20), it is pertinent to investigate postexercise LV function in such individuals. An ideal op- portunity for study presented itself with the London Mara- thon where around 30,000 participants, mainly recreational and “charity” runners, take part annually. To date, there are few published papers assessing LV function pre and postmarathon (17,18,21,22,28). Of these studies, Perrault et al. (22) investigated only LV function, and Ohman et al. (21) assessed primarily biochemical pa- rameters in small and homogenous samples of well-trained males. Manier et al. (18) investigated slightly more diverse subjects, but the sample size was small (N = 11), and no biochemical markers were assessed. Siegel et al. (28) con- centrated upon biochemical parameters and reported spo- radic alterations in cTnT and cTnI in a diverse group who participated in five different marathons. Limited attempts were made to link functional and biochemical data or in- vestigate specifically the influence of subject age or finish- ing time. Lucia et al. (17) investigated LV functional and biochemical data in 22 runners (age range 23– 44 yr) both pre- and postrace. Limited evidence of LV systolic dysfunc- Address for correspondence: Dr. Keith George. Research Institute for Sport and Exercise Sciences, Henry Cotton Campus, Liverpool John Moores Uni- versity, Liverpool, L3 2ET, United Kingdom; E-mail: k.george@livjm.ac.uk. Submitted for publication January 2004. Accepted for publication June 2004. 0195-9131/04/3610-1709 MEDICINE & SCIENCE IN SPORTS & EXERCISE ® Copyright © 2004 by the American College of Sports Medicine DOI: 10.1249/01.MSS.0000142408.05337.49 1709