Background: The hemodynamic and cardiac responses to exercise have been widely investigated in adults.\nHowever, little is known regarding myocardial performance in response to a short bout of maximal exercise in\nadolescents. We therefore sought to study alterations in myocardial function and investigate sex-influences in\nyoung athletes after maximal cardiopulmonary testing.\nMethods: 51 adolescent (13-19 years old) floor-ball players (24 females) were recruited. All subjects underwent a\nmaximal exercise test to determine maximal oxygen uptake (VO2max) and cardiac output. Cardiac performance was\ninvestigated using conventional and tissue velocity imaging, as well as 2D strain echocardiography before and\n30 minutes following exercise. Arterio-ventricular coupling was evaluated by means of single beat ventricular elastance\nand arterial elastance.\nResults: Compared to baseline the early diastolic myocardial velocity (E?LV) at the basal left ventricular (LV) segments\ndeclined 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\nfor both). Similarly, 2D strain decreased significantly following exercise (2D strain LV: from 21.5 +/- 2.4 to 20.2 +/- 2.7%\nin females, and from 20 +/- 1 to 17.9 +/- 1.5% in males, p < 0.05 for both). However, there were no significant changes\nin LV contractility estimated by elastance in either sex following exercise (p > 0.05). Arterial elastance) Ea) at baseline\nwas identified as the only predictor of VO2max in males (r = 0.76, p < 0.001) but not in females (p > 0.05).\nConclusions: The present study demonstrates that vigorous exercise of short duration results in a significant decrease\nof longitudinal myocardial motion in both sexes. However, in view of unaltered end systolic LV elastance (Ees), these\nreductions most probably reflect changes in the loading conditions and not an attenuation of myocardial function\nper se. Importantly, we show that arterial load at rest acts as a strong predictor of VO2max in males but not in female\nsubjects.
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