Antidepressant choice in the patient with cardiac disease: lessons from the Cardiac Arrhythmia Suppression Trial (CAST) studies.

At one point it was believed that the systematic study of the cardiovascular effects of therapeutic levels of tricyclic antidepressants had established the relative safety of these drugs even in patients with significant cardiovascular disease. However, recent studies demonstrating a deleterious effect of antiarrhythmic agents in patients with ischemic heart disease have significant implication for conclusions about tricyclic safety. Studies in cardiology designed to demonstrate that suppression of ventricular arrhythmia in the post-myocardial infarction period would reduce mortality produced the unexpected opposite result, i.e., patients treated with class I antiarrhythmic drugs actually had an increase in their mortality rate. Since tricyclics are classified as type IA antiarrhythmics, it would seem prudent to assume that they have similar risks unless proven otherwise. Other drugs such as the serotonin selective reuptake inhibitors or bupropion, which may be safer than the tricyclics from the cardiovascular perspective, have yet to establish their efficacy in the older and more severely depressed patient population.