[Mechanism of overshoot elevation of left ventricular ejection fraction during recovery after exercise in normal subjects and patients with coronary artery disease, assessed by 99mTc exercise radionuclide ventriculography].
An "overshoot" (OS) elevation of ejection fraction above resting levels has been demonstrated during recovery after exercise. To characterize the hemodynamic changes during recovery after bicycle exercise, we used radionuclide ventriculography under the Swan-Ganz catheter insertion in 16 normal subjects and 15 patients with coronary artery disease (CAD) at rest, during bicycle exercise and after exercise periods. In normal subjects, the ejection fraction increased from resting value during peak exercise, and showed overshoot elevation in the early recovery period. In patients with CAD, the ejection fraction decreased from resting value during peak exercise, then showed overshoot elevation in the early recovery period. In normal subjects, the end-diastolic volume (EDV) and the end-systolic volume (ESV) decreased from resting value during OS. In patients with CAD, the EDV at OS was not different from that at rest, the ESV decreased from resting value during OS. The systemic vascular resistance increased from resting value during OS. The systolic blood pressure/ESV, index for ventricular contractility, increased from resting value during OS in both groups. Thus, the decreased systemic vascular resistance does not playing a major role during recovery after exercise, whereas enhanced contractility is evident in both normal subjects and patients with CAD.
Second Department of Internal Medicine, Gunma University School of Medicine.
S
S
Kubota
T
T
Iizuka
N
N
Isobe
H
H
Nagaoka
S
S
Imai
T
T
Suzuki
D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D015635:Radionuclide Ventriculography; D013318:Stroke Volume / Q000502:physiology*