Detrimental effect of propranolol in patients with coronary arterial spasm countered by combination with diltiazem

Abstract

This study determines, with quantitative variables, if propranolol is detrimental in patients with documented coronary arterial spasm and if this drug can be used in combination with calcium antagonists. Eleven patients with documented coronary spasm were entered prospectively in a study with 4 phases of 2 days each: (1) control, (2) diltiazem or propranolol (mean 225 +/- 75 mg/day), (3) propranolol or diltiazem (360 mg/day), (4) propranolol and diltiazem. The effects of the drugs were assessed by the detection of ischemic electrocardiographic episodes (24-hour electrocardiographic monitoring) and provocative tests with ergonovine. During the period of treatment with propranolol, the number and the duration of attacks increased and provocative tests had positive results in all patients. Diltiazem completely abolished spontaneous episodes, but 6 of 11 patients remained sensitive to the administration of ergonovine. The association of the 2 drugs led to a disappearance of ischemic episodes. In conclusion, propranolol is ineffective in patients with coronary artery spasm. It can be used in combination with diltiazem, but without any advantage over diltiazem alone.