Abstract

Cardiovascular responses to isometric and isotonic efforts were evaluated by radionuclide angiography in 2 groups of top endurance (A) and strength athletes (B). Group A (20.8 yrs.;range 19-33) included 8 cyclists and 2 marathon runners; Group B (25.8 yrs.;range 17-36) included 3 wrestlers, 3 weight lifters and 2 body-builders. Changes in heart rate (HR), blood pressure (BP) and ventricular volumes, ejection fraction (EF), peak ejection rate (PER) and peak filling rate (PFR) were evaluated either at rest, during 4 min of isometric effort (handgrip, HG) at 50 MVC, and during isotonic effort on a semisupine cycloergometer (C) with increasing work loads (50 W/step). Elevated resting BP was found in 5 athletes of Group A and 1 of Group B. During cycling, systolic BP increased in all subjects from baseline values of 120+-13 to 213+-35 mm Hg, and from 143+-18 to 233+-36 mm Hg in Groups A and B, respectively. Diastolic BP increased in 5 subjects of Group B and 1 subject of Group A. During isotonic exercise, stroke volume evaluated by nuclear ventriculography increased from 89+-15 to 115+-10 ml in Group A but remained unchanged in group B (79+-15 vs 79+-20 ml). Ejection fraction increased in all athletes during C, but decreased by more than 5 in 4 endurance athletes during HG. Both types of exercise induced an increase of cardiac index (min/m) from a baseline value of 2.8+-0.5 to 3.5+-1.1 during HG and to 10.3+-1.3 during C in Group A, and from 2.8+-0.3 to 3.3+-1.0 and to 6.2+-1.6 in Group B, during HG and C, respectively. Verf.-Ref.