title: Gender differences in myocardial function and arterio-ventricular coupling in response to maximal exercise in adolescent floor-ball players.
abstract: BACKGROUND
  The hemodynamic and cardiac responses to exercise have been widely investigated in adults. However, little is known regarding myocardial performance in response to a short bout of maximal exercise in adolescents. We therefore sought to study alterations in myocardial function and investigate sex-influences in young athletes after maximal cardiopulmonary testing.
  
  
  METHODS
  51 adolescent (13-19 years old) floor-ball players (24 females) were recruited. All subjects underwent a maximal exercise test to determine maximal oxygen uptake (VO2max) and cardiac output. Cardiac performance was investigated using conventional and tissue velocity imaging, as well as 2D strain echocardiography before and 30 minutes following exercise. Arterio-ventricular coupling was evaluated by means of single beat ventricular elastance and arterial elastance.
  
  
  RESULTS
  Compared to baseline the early diastolic myocardial velocity (E'LV) at the basal left ventricular (LV) segments declined significantly (females: E'LV: 14.7 +/- 2.6 to 13.6 +/- 2.9 cm/s; males: 15.2 +/- 2.2 to 13.9 +/- 2.3 cm/s, p < 0.001 for both). Similarly, 2D strain decreased significantly following exercise (2D strain LV: from 21.5 +/- 2.4 to 20.2 +/- 2.7% in females, and from 20 +/- 1 to 17.9 +/- 1.5% in males, p < 0.05 for both). However, there were no significant changes in LV contractility estimated by elastance in either sex following exercise (p > 0.05). Arterial elastance) Ea) at baseline was identified as the only predictor of VO2max in males (r = 0.76, p < 0.001) but not in females (p > 0.05).
  
  
  CONCLUSIONS
  The present study demonstrates that vigorous exercise of short duration results in a significant decrease of longitudinal myocardial motion in both sexes. However, in view of unaltered end systolic LV elastance (Ees), these reductions most probably reflect changes in the loading conditions and not an attenuation of myocardial function per se. Importantly, we show that arterial load at rest acts as a strong predictor of VO2max in males but not in female subjects.
authors.affiliation: Department of Medicine, Unit of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Fomin
authors.affiliation: Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.|School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Cristina
authors.initials: C
authors.lastname: Da Silva
authors.affiliation: Department of Medicine, Unit of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Ahlstrand
authors.affiliation: Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Sahlén
authors.affiliation: Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Lund
authors.affiliation: Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Marcus
authors.initials: M
authors.lastname: Stahlberg
authors.affiliation: Department of Medicine, Unit of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Gabrielsen
authors.affiliation: Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.|School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.|Department of Clinical Physiology and Cardiology, Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden.
authors.forename: Aristomenis
authors.initials: A
authors.lastname: Manouras
keywords: Adolescent; Contractility; Echocardiography; Elastance; Exercise; Exercise stress test; Peak VO2; Sex; Tissue Doppler Imaging