Left Ventricular Function at Rest, during Exercise and Recovery Period in Trained Athletes: Assessment with Radionuclide Angiography

Abstract

The aim of this research was to define left ventricular performance during supine bicycle exercise in athletes. Fifteen young male trained rugby players underwent gated radionuclide left ventriculography at rest, during intermediate workload (E-I), during submaximal workload (E-II) and during recovery period (RP). Left ventricular ejection fraction (EF) at rest averaged 70.0 ± 9.7, slightly increased at E-I (74.9 ± 6.8) but significantly increased at E-II (78.0 ± 7.1; p < 0.05) and at RP (77.1 ± 5.7; p < 0.05). At rest, the apical segment had a subtotal emptying, which decreased during exercise, with an evident increase in anteroseptal and inferoposterior wall motion, suggesting a geometric remodelling of ventricular cavity shape. The peak ejection rate (PER) had a remarkable and significant increase at E-I, E-II and RP, with concordant shortening of time to PER. The peak filling rate (PFR) had a remarkable and significant increase at E-I and E-II; at RP, PFR came back to the resting values, with concordant behaviour of time to PFR. The end-diastolic volume index had a very small increase at E-I, E-II and RP; the end-systolic volume index clearly decreased at E-I (-10%), E-II (-23%) and RP (-25%), inducing an increase in the stroke volume index (+27%) and in the cardiac output index (+225%) at E-II. These findings suggested that during exercise our young athletes had an increase in cardiac output partly derived from stroke volume increase, but mainly from heart rate increase. The increase in EF was accompanied by a substantially unchanged end-diastolic volume, while the end-systolic volume was clarly reduced. The cardiac adaptation to training in our athletes seemed to lead to an increased contractile performance but did not rely on the Frank-Starling mechanism.

Left Ventricular Function in Insulin-Dependent and in Non-Insulin-Dependent Diabetic Patients: Radionuclide Assessment

“…The comparison between the two groups, matched for age, sex and body mass index, does not indicate any difference as well as microangio pathic complications or autonomic neuropathy; besides they do not seem to prominently induce a parametric impairment of ventricular function [6] or present with it a weak correlation [10]. Impaired diastolic function and particularly the isolated presence of abnormal ventricular filling is clearly shown by the lower PFR/PER ratio in the NIDDM group; the PFR/PER ratio was close to 1 in healthy subjects, athletes [18] and compensated IDDM patients [16]; on the contrary it was reduced in coronary and hypertensive patients [19], A possible explanation of diastolic impairment might be the consequence of an increased left ventricular mass/ body surface area in NIDDM patients even if this was excluded by échocardiographie examinations in our pa-tients [10]. The induction mechanism of left ventricular hypertrophy is still not clear; in the absence of high blood pressure levels, such as in our patients, a different process might be involved: hyperinsulinemia, or associated meta bolic abnormalities may enhance left ventricular mass [20] and may lead to lower left ventricular compliance [3,21].…”