Effect of propranolol on diastolic time during exercise.
To evaluate the effect of propranolol on diastolic time (DT) during uninterrupted upright exercise, 11 men with normal coronary arteries receiving oral propranolol and 10 men with coronary artery disease (CAD) were studied by ear densitography. The DT-heart rate (HR) regression equation during exercise obtained from persons without CAD receiving propranolol was DT = e(6.923-0.014 X HR), which was not statistically different compared to that of normal volunteers with no medication. All 10 men with CAD had ischemic electrocardiographic responses at peak exercise with no medication but had no signs of ischemia during exercise after receiving oral propranolol therapy. Although propranolol caused no significant difference in the DT-HR relation in patients with CAD at 1-min exercise, a significant difference in the DT-HR relation was observed after propranolol therapy at peak exercise. In addition to negative chronotropic action (leftward shift along the DT-HR curve), prevention of disproportionate DT shortening at peak exercise (upward shift of the DT-HR curve) with propranolol through its beneficial action on myocardial ischemia tends to increase myocardial perfusion in patients who, when off propranolol, had ischemic response to exercise.
Second Department of Internal Medicine, Kansai Medical University, Moriguchi City, Japan.
T
T
Sugiura
T
T
Iwasaka
T
T
Hasegawa
N
N
Takahashi
M
M
Matsutani
M
M
Inada
D000328:Adult; D000790:Angiocardiography; D003327:Coronary Disease / Q000188:drug therapy / Q000503:physiopathology; D004569:Electroencephalography; D015444:Exercise; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D011433:Propranolol / Q000494:pharmacology* / Q000627:therapeutic use
D011433:Propranolol