Effects of bepridil on silent myocardial ischemia and eicosanoid metabolism in chronic stable angina pectoris after healing of myocardial infarction.
To investigate the effects of bepridil on silent myocardial ischemia and on eicosanoid metabolism, 10 patients with chronic stable angina underwent exercise treadmill testing and 48-hour ambulatory electrocardiographic monitoring both before and after 4 weeks of bepridil administration (150 mg/day). Fasting venous levels of thromboxane B2, 6-keto-prostaglandin F1 alpha, and leukotriene C4 were measured by radioimmunoassay. Bepridil decreased heart rate responses to daily activities during ambulatory monitoring, and significantly (p < 0.05) reduced the median frequency and duration of silent myocardial ischemic episodes (from 5.5 to 0 events/48 hours and from 86 to 0 minutes/48 hours respectively). Bepridil significantly decreased the blood pressure heart rate product at peak exercise and significantly prolonged the mean exercise tolerance time (from 456.6 to 527.0 second). Bepridil also significantly decreased the plasma levels of thromboxane B2 and leukotriene C4 at rest. These results suggest that bepridil may reduce silent myocardial ischemic episodes either by the reduction of cardiac oxygen demand during daily activities and exercise stress, or by controlling coronary and systemic vasomotor tone. The drug also has a salutary effect on eicosanoid metabolism, to which its efficacy on silent myocardial ischemic episodes may be related.
Takase
B
B
First Department of Internal Medicine, National Defense-Medical College, Saitama, Japan.
Kurita
A
A
Hikita
H
H
Uehata
A
A
Nishioka
T
T
Maruyama
T
T
Mizuno
K
K
Nakamura
H
H
Kanda
Y
Y
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000188:drug therapy; D001095:Arachidonic Acids / Q000097:blood*; D015764:Bepridil / Q000627:therapeutic use*; D002908:Chronic Disease; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D017997:Leukotriene C4 / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000517:prevention & control; D017202:Myocardial Ischemia / Q000097:blood* / Q000188:drug therapy*; D011863:Radioimmunoassay; D016037:Single-Blind Method; D013929:Thromboxane B2 / Q000097:blood
D001095:Arachidonic Acids; D017997:Leukotriene C4; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D015764:Bepridil