Elimination of unstable angina by diltiazem under temporary pacing.

We describe two patients in whom spontaneous angina following acute myocardial infarction (postinfarction angina caused by coronary artery spasm) and worsening angina were successfully eliminated after clinical dosage of oral diltiazem, while marked sinus node suppression developed and temporary pacing was performed. The patients were females (one was 67 years and one was 64 years old), and had no history of sinus node dysfunction. The occurrence of the adverse effect was not during angina, and the intervals between the initiation of diltiazem and the occurrence were 6 days after 120 mg/day in one patient, and 4 h after a single administration of 60 mg in the other. Diltiazem is also efficacious in the elimination of unstable angina, however one should note that diltiazem may remarkably suppress not only atrioventricular node activity but also sinus node activity in some patients.