title: Left ventricular wall segment motion after ultra-endurance exercise in humans assessed by myocardial speckle tracking.
abstract: OBJECTIVE
  Assessment of the left ventricular responses to prolonged exercise has been limited by technology available to assess cardiac tissue movement. Recently developed strain and strain rate imaging provide the unique opportunity to assess tissue deformation in all planes of motion.
  
  
  RESULTS
  Nineteen runners (mean+/-SD age; 41+/-9 years) were assessed prior to and within 60 min (34+/-10 min) of race finish (Comrades Marathon, 89 km). Standard echocardiography assessed ejection fraction and the ratio of early to atrial (E/A) peak transmitral blood flow velocities. Myocardial speckle tracking determined segmental strain as well as systolic and diastolic strain rates in radial, circumferential, and longitudinal planes. Cardiac troponin T (cTnT) assessed cardiomyocyte insult. Ejection fraction (71+/-5 to 64+/-6%) and E/A (1.47+/-0.35 to 1.25+/-0.30) were reduced (P<0.05). Peak strain and peak systolic and diastolic strain rates were altered post-race in circumferential (e.g. peak strain reduced from 21.3+/-2.4 to 17.3+/-3.2%, P<0.05) and radial planes. Some individual heterogeneity was observed between segments and planes of motion. A post-race elevation in cTnT (range 0.013-0.272 microg/L) in 5/12 runners did not differentiate changes in LV function.
  
  
  CONCLUSIONS
  Completion of the Comrades Marathon resulted in a depression in ejection fraction, E/A, as well as radial and circumferential strain and strain rates. Group data, however, masked some heterogeneity in cardiac function.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, 15-21 Webster Street, Liverpool L3 2ET, UK. k.george@livjm.ac.uk
authors.forename: Keith
authors.initials: K
authors.lastname: George
authors.forename: Rob
authors.initials: R
authors.lastname: Shave
authors.forename: David
authors.initials: D
authors.lastname: Oxborough
authors.forename: Tim
authors.initials: T
authors.lastname: Cable
authors.forename: Ellen
authors.initials: E
authors.lastname: Dawson
authors.forename: Nigel
authors.initials: N
authors.lastname: Artis
authors.forename: David
authors.initials: D
authors.lastname: Gaze
authors.forename: Tamara
authors.initials: T
authors.lastname: Hew-Butler
authors.forename: Karen
authors.initials: K
authors.lastname: Sharwood
authors.forename: Tim
authors.initials: T
authors.lastname: Noakes
mesh_terms: D000328:Adult; D017079:Exercise Tolerance; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D012420:Running; D013318:Stroke Volume; D014463:Ultrasonography; D016277:Ventricular Function, Left