Effects of diltiazem-induced calcium blockade upon exercise capacity in effort angina due to chronic coronary artery disease.
Few data are available regarding the effects of calcium blockade upon exercise tolerance in patients with stable effort angina due to coronary artery disease (CAD). Therefore we compared the effects of the calcium blocking agent, diltiazem (D), to placebo (P) in 12 patients with chronic effort angina and catheterization documented fixed CAD. The 8-week total protocol consisted of a 1-week baseline period followed by the double-blind randomized crossover alternate 1-week administration of P and D in doses of 120, 180, and 240 mg. Maximal exercise tests (MET) were performed at the end of each 1-week period, while rest radionuclide ventriculography (RVG) was obtained during 240 mg D and corresponding crossover P. Resting heart rate decreased from baseline and initial P at D doses of 60 and 240 mg, but not from P during crossover period. No changes were observed at any dose of D either at rest or during MET in systolic blood pressure or rate . pressure double product. D at 240 mg, but not lower doses, increased MET duration (437 vs 490 seconds, p less than 0.01) and time to angina (383 vs 441 seconds, p less than 0.01). Ejection fraction by RVG was greater with D than P (0.54 vs 0.50, p less than 0.05). Thus these data indicate that calcium blockade with diltiazem provides antianginal efficacy by reducing myocardial oxygen demand, and increases exercise tolerance without depression of myocardial performance in effort angina patients with fixed chronic CAD.
D000368:Aged; D000787:Angina Pectoris / Q000209:etiology / Q000503:physiopathology*; D001552:Benzazepines / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D002908:Chronic Disease; D003327:Coronary Disease / Q000150:complications*; D004110:Diltiazem / Q000494:pharmacology*; D005080:Exercise Test; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging
D001552:Benzazepines; D004110:Diltiazem; D002118:Calcium