Coronary dilation with nitrocompounds and calcium antagonists.
The vasodilatory effects of nitrocompounds and calcium antagonists on epicardial coronary arteries represent substantial antianginal mechanisms in the presence of coronary vasospasm or eccentric coronary stenoses. With high doses of nitrocompounds, angiographically normal coronary segments can be dilated by an average of approx. 30%, some coronary stenoses even by up to 100%, usually without severe reduction of blood pressure. With calcium antagonists, a similar extent of dilation of normal coronary arteries and eccentric stenoses can be obtained. Our own group demonstrated an average dilation of normal coronary arteries of about 20% after intravenous administration of dihydropyridine calcium antagonists; however, the average systolic blood pressure dropped below 100 mmHg after these compounds. Hence, although in isolated human coronary arteries high concentrations of calcium antagonists were shown to induce a considerably greater vasodilation than nitrocompounds, the early drop in blood pressure prohibits a higher dosage of calcium antagonists in vivo. In the presence of coronary artery disease, particularly when associated with coronary vasospasm, a combination of the two groups of compounds might be recommendable, since an addition of the effects of coronary vasomotor tone is likely. Furthermore, the antianginal effects of a reduction of preload and afterload are complementary.
Jost
S
S
Department of Cardiology, Hannover Medical School, FRG.
Rafflenbeul
W
W
Lichtlen
P R
PR
D000787:Angina Pectoris / Q000188:drug therapy; D000818:Animals; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000188:drug therapy*; D006801:Humans; D009574:Nitro Compounds / Q000627:therapeutic use*; D014664:Vasodilation / Q000187:drug effects
D002121:Calcium Channel Blockers; D009574:Nitro Compounds