Right bundle branch block and bradycardia in amitriptyline toxicity

Cardiovascular events are the leading cause of fatal outcome from tricyclic antidepressant (TCA) overdose; cardiotoxicity as dysrhythmias and hypotension. Electrocardiogram (ECG) abnormalities usually precede the development of significant, clinically evident cardiovascular disease, and so the ECG has manifests clinically emerged as a valuable tool in the assessment of TCA toxicity. Cardiac toxicity secondary to TCAs is due mainly to sodium-channel blockade and slowing of phase 0 depolarization of the action potential resulting in slowing of conduction through the His-Punkinje system and myocardium. Sinus tachycardia is the most common manifestation seen, other ECG changes, which are seen are premature ventricular contractions, ventricular tachycardia and fibrillation, supraventricular tachycardia with aberrancy, sinus arrest, idioventricular rhythm, pulseless electrical activity, QRS/QT/PR prolongation, rightward terminal QRS axis, increased amplitude of R aVR , atrioventricular blocks, and uncommonly as bundle branch block. Here, we discuss the ECG alterations as a right bundle branch block in a patient who was intoxicated with amitriptyline.