Experimental amitriptyline intoxication: electrophysiologic manifestations and management

Area of Science:

• Cardiology
• Pharmacology
• Toxicology

Background:

• Amitriptyline intoxication can lead to severe ventricular arrhythmias.
• The mechanisms and management of these arrhythmias are not fully understood.

Purpose of the Study:

• To investigate the cardiac effects of amitriptyline infusion in dogs.
• To evaluate the efficacy of sodium bicarbonate in treating amitriptyline-induced ventricular arrhythmias.

Main Methods:

• Cardiac effects of amitriptyline infusion were studied in anesthetized and awake dogs.
• Ventricular tachyarrhythmias were induced and treated with sodium bicarbonate.

Main Results:

• Amitriptyline increased heart rate, QRS duration, and conduction intervals (AH, HV).
• Ventricular tachyarrhythmias developed after significant QRS widening.
• Sodium bicarbonate rapidly reversed all induced ventricular arrhythmias without altering serum electrolytes or drug levels.

Conclusions:

• Amitriptyline intoxication frequently causes ventricular tachyarrhythmias associated with impaired intraventricular conduction.
• Sodium bicarbonate is an effective therapy for amitriptyline-induced ventricular arrhythmias.