Incidence of late arrhythmias following tricyclic antidepressant overdose.

The case records of 129 patients hospitalized because of tricyclic antidepressant (TCA) poisoning were analyzed to determine the incidence of late arrhythmias. All patients who developed cardiovascular or central nervous system complications of TCA overdose did so within 1 h of admission. No patients developed arrhythmias once they became alert and had a normal cardiogram for 1 h; a 24-h period of inpatient monitoring is suggested as sufficient follow-up for such patients provided they have no underlying cardiac disease.