Cardiac abnormalities in poisoning with tricyclic antidepressants.

Of 80 consecutive admissions to a general hospital for drug overdose, 10 had taken one or other of the tricyclic antidepressants. All 10 had abnormalities of cardiac conduction as shown by prolonged Q-T(e) intervals, and eight had S-T segment and T-wave changes. Five of the 10 patients had arrhythmias and two of these died. Continuous electrocardiographic monitoring is recommended in patients with overdosage of tricyclic antidepressants.