TRICYCLIC OVERDOSE CAUSING SUSTAINED MONOMORPHIC VENTRICULAR-TACHYCARDIA

Desipramine belongs to a group of psychotropic compounds called tricyclic antidepressants that have similar chemical structures and share a variety of pharmacologic actions. They tend to be lipophilic and are found in high concentrations in the myocardium of treated patients.1 Actions responsible for most of their cardiovascular effects include anticholinergic properties, an ability to block norepinephrine reuptake and a type 1 antiarrhythmic action.1,2 A variety of cardiac dysrhythmias have been associated with tricyclic antidepressant usage and especially with overdosage.3 Sustained ventricular arrhythmias are an uncommon complication of nonfatal tricyclic antidepressant overdose4 and usually consist of polymorphous ventricular tachycardia (or ventricular fibrillation). In the present report, we describe a young person without apparent organic heart disease who ingested a large amount of desipramine and who presented with sustained monomorphic ventricular tachycardia which persisted over a 3-day period. © 1992.