title: Cardiac electromechanical delay is increased during recovery from 40 km cycling but is not mediated by exercise intensity.
abstract: Cardiac electrical-mechanical delay (cEMD), left ventricular (LV) function, and cardiac troponin I (cTnI) were assessed after 40 km cycle time trials completed at high (HIGH) and moderate (MOD) intensities in 12 cyclists. Echocardiograms and blood samples were collected before, 10, and 60 min after cycling. cEMD as assessed by time from QRS onset to peak systolic (S') tissue velocity was lengthened after both bouts of cycling but was not mediated by cycling intensity (HIGH: 174 ± 52 vs 198 ± 26 ms; MOD: 151 ± 40 vs 178 ± 52 ms, P < 0.05). Global LV systolic function was unaltered by exercise. cEMD from QRS to peak early (E') diastolic tissue velocity was also increased post-exercise (HIGH: 524 ± 95 vs 664 ± 68 ms; MOD: 495 ± 62 vs 604 ± 91 ms, P < 0.05). Indices of LV diastolic function was reduced after cycling but were not mediated by exercise intensity. cTnI was elevated in two participants after HIGH trial (0.06 ug/L; 0.04 ug/L) and one participant after MOD trial (0.02 ug/L). While cEMD is lengthened and LV diastolic function was reduced post-cycling, altering time-trial intensity had little impact upon cEMD, LV function, and cTnI release.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK. F.chan-dewar@2006.ljmu.ac.uk
authors.forename: F
authors.initials: F
authors.lastname: Chan-Dewar
authors.forename: W
authors.initials: W
authors.lastname: Gregson
authors.forename: G
authors.initials: G
authors.lastname: Whyte
authors.forename: J
authors.initials: J
authors.lastname: King
authors.forename: D
authors.initials: D
authors.lastname: Gaze
authors.forename: L E
authors.initials: LE
authors.lastname: Carranza-García
authors.forename: A
authors.initials: A
authors.lastname: Legaz-Arrese
authors.forename: K
authors.initials: K
authors.lastname: George
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D055724:Electrophysiological Phenomena / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D013599:Systole / Q000502:physiology; D019210:Troponin I / Q000097:blood; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D019210:Troponin I