Chronic recurrent angina.
The natural history of variant angina is described in a patient with multiple exacerbations and remissions over a period of several years. Constant in-hospital electrocardiographic monitoring for 26 days documented 569 episodes of ST elevation, 89% of which were asymptomatic. Episodes ranged in duration from 15 seconds to 11 1/2 minutes, with 4% of episodes associated with premature ventricular contractions. Over the course of hospitalization, the episodes of ST elevation decreased in frequency and length, as did episodes of pain. During this period, a number of therapeutic agents, including propranolol, indomethacin, and chlorpheniramine were evaluated using double-blind crossover trials. No agent had a significant beneficial effect on the course of the disease, and there was an increase in the length of episodes with high doses of propranolol. Because of the great variability in the course of this disease, only double-blind crossover trials should be allowed to dictate the efficacy of therapeutic agents.