ECG changes in pediatric patients on tricyclic antidepressants, desipramine, and imipramine

To determine if there is an altered pattern of cardiac electrical activity in children treated with tricyclic antidepressants, desipramine, or imipramine, which may predispose these patients to sudden death.

All patients in a child psychiatry practice from 1989 to 1993 in Calgary, Alberta, treated with desipramine or imipramine with both pre- and post-treatment electrocardiograms (ECGs) were included in the study (n = 21; ages 8 to 17 years). Thirty-six blinded post-treatment ECGs were analysed for interval measurement and compared to the pretreatment ECGs.

Drug dosages ranged from 25 mg to 125 mg per day and treatment duration ranged from 1 to 49 months. Seven of 21 patients were concurrently receiving an antipsychotic medication (pericyazine). The maximal increase in PR, and QRS, and QT interval changes were 40 msec and 70 msec, respectively, with most patients demonstrating no significant changes in the ECG intervals. The QT interval was corrected for heart rate (QTc). No significant arrhythmias or tachycardias were observed. ECG interval changes were not related to drug dosage, age, treatment duration or plasma levels.

No consistent pattern of ECG interval changes including the QTc interval was observed in children on desipramine and imipramine.