Verapamil: its potential for causing serious complications in patients with hypertrophic cardiomyopathy.

Verapamil is extremely effective in the treatment of patients with hypertrophic cardiomyopathy. However, the basic physiologic actions of the drug may lead to serious adverse effects. An appreciation of this and an understanding of when these adverse effects are most likely to occur will minimize the potential of verapamil to cause serious complications in patients with hypertrophic cardiomyopathy.