effects of prolonged exercise on left ventricular function in male recreational athletes.
Published: 2006
Language: eng
Number of pages: 105
ISBN-13: 9780494163443
Description: We hypothesized that altered left ventricular function would be evident in a decreased dose-response to dobutamine, manifested in impaired inotropic and chronotropic function after prolonged exercise.Prolonged exercise is a significant challenge to cardiovascular regulation; however, studies of its effect on cardiac function are equivocal. Objectives of the current study were to determine if cardiac fatigue can be observed and if beta-adrenergic desensitization occurs.Subjects included 12 healthy, males (43.5 +/- 6.5 years). Maximal oxygen consumption was determined from an incremental cycle ergometer test (HRmax = 175.6 +/- 6.6 bpm). A second test consisted of a prolonged exercise challenge (120 min at 75% HRmax) and baseline/recovery dobutamine challenges. Measures were obtained through M-mode and two-dimensional echocardiography. Left ventricular dysfunction was not reported during a 120 minute bout of cycle exercise at 75% HRmax in a middle aged, male cohort; however, a trend for reduced LV function was reported in a post-exercise dobutamine challenge.
Notes: Source: Masters Abstracts International, Volume: 44-06, page: 2786.

Thesis (M.Sc.)--University of Toronto, 2006.

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