Objective: With the increased use of tricyclic antidepressants in children, and several reports of several sudden deaths associated with desipramine (DMI) treatment, systematic study of their cardiac effects is indicated. In the present study, DMI's and clomipramine's (CMI) short-term effects on the electrocardiogram (ECG) were compared, as well as the long-term effects of CMI.
Method: The ECGs of 47 children and adolescents in treatment trials were examined at baseline, after 5 weeks of CMI and of DMI treatment, and during CMI maintenance (mean duration 24.6 months).
Results: At 5 weeks of CMI and of DMI treatment, the heart rate, PR, QRS, and QT-corrected (QTc) intervals on ECG were significantly increased from baseline (p < .05); DMI increased PR and QRS intervals more than CMI (p < .05), and CMI increased QTc more (p < .05). Tachycardia was the most common change (36%). More patients experienced an incomplete intraventricular conduction delay during DMI treatment (23%, 9/39) than during CMI (2%, 1/47) (p < .05). Four patients (9%) acutely developed a prolonged QTc during either DMI or CMI. Long-term maintenance ECGs during CMI treatment (n = 25) were not significantly different from that at week 5, although some individuals developed or resolved specific ECG changes.
Conclusion: CMI and DMI both produced ECG changes typically reported for tricyclic antidepressants, and they differed on specific ECG changes. Changes in ECG measures for individuals from short to long term suggest that continued monitoring is required.