Cardiac effects of antidepressant drugs. A comparison of the tricyclic antidepressants and fluvoxamine.

1 The cardiovascular effects of the tricyclic antidepressants (TCAs) are reviewed and compared with those of fluvoxamine, a new 5-hydroxytryptamine (5-HT) re-uptake inhibitor. 2 The TCAs have important effects on the heart, related to their anticholinergic and quinidine-like properties. The major side effects in therapeutic dosage include heart rate increase, postural hypotension and slight prolongation of the intraventricular conduction time and QT interval. In toxic dosage (or normal dosage in patients with severe heart disease) both advanced heart block and ventricular arrhythmias can occur, together with clinically important loss of myocardial contractile force. 3 Fluvoxamine has no effects on the heart except for a statistically (but not clinically) significant slowing of the heart rate.