Combination therapy with diltiazem and propranolol: precipitation of congestive heart failure.

Although congestive heart failure has been reported with the combination of a beta blocker and either verapamil or nifedipine, it has not previously been reported for combination therapy that includes diltiazem. The following case documents the occurrence of clinical congestive failure in a patient with baseline left ventricular dysfunction and severe angina pectoris. Although the patients had tolerated propranolol therapy for years without difficulty, and high-dose diltiazem monotherapy with an excellent clinical response, the combination of diltiazem and propranolol resulted in the development of congestive heart failure. Thus, although generally well tolerated, given the suitable scenario of reduced left ventricular function, the combination of diltiazem and a beta blocker may adversely affect left ventricular performance.