Effect of nipradilol on silent myocardial ischemia, plasma beta-endorphin, and bradykinin in chronic stable angina.
OBJECTIVE
This study was undertaken to investigate the effect of nipradilol on the total ischemic burden and on plasma levels of beta-endorphin and bradykinin.


METHODS
Sixteen patients with chronic stable angina were subjected to exercise treadmill testing and 24-h ambulatory electrocardiogram (ECG).


RESULTS
Nipradilol significantly decreased both mean heart rate and mean pressure rate product at submaximal and maximal exercise. It significantly improved exercise-induced maximal ST-segment depression from -2.7 +/- 0.5 mm to -1.3 +/- 0.6 mm (p < 0.05) and reduced the number of leads with significant ST-segment depression (4.0 +/- 1.2 vs. 2.0 +/- 1.8, p < 0.05). Silent ischemic episodes recorded in 24-h ambulatory ECG were significantly decreased by nipradilol administration, concomitantly with a decrement of mean heart rate and observed maximal heart rate. Patients with exercise-induced silent myocardial ischemia showed significantly increased plasma levels of beta-endorphin during both the placebo and nipradilol phases of the study. However, during the nipradilol phase, bradykinin did not change significantly at rest and at peak exercise.


CONCLUSIONS
Nipradilol effectively controls exercise-induced myocardial ischemia and silent myocardial ischemic episodes, and does not influence the response of plasma levels of beta-endorphin to exercise stress testing in patients with exercise-induced silent myocardial ischemia.
Takase
B
B
First Department of Internal Medicine, National Defense Medical College, Saitama, Japan.
Kurita
A
A
Uehata
A
A
Hikita
H
H
Nishioka
T
T
Mitani
H
H
Satomura
K
K
Mizuno
K
K
Nakamura
H
H
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001920:Bradykinin / Q000097:blood* / Q000187:drug effects; D002908:Chronic Disease; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000188:drug therapy* / Q000503:physiopathology; D011412:Propanolamines / Q000627:therapeutic use*; D011863:Radioimmunoassay; D001615:beta-Endorphin / Q000097:blood* / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D011412:Propanolamines; D001615:beta-Endorphin; C036089:nipradilol; D001920:Bradykinin