Verapamil-Sensitive Idiopathic Left Ventricular Tachycardia in a 6-Month-Old

Abstract

Idiopathic left ventricular tachycardia of the Belhassen type is rare in infants. We present a 6-month-old infant girl with a wide-complex tachycardia with right bundle branch block QRS morphology, a superior axis, and atrioventricular dissociation, consistent with a left anterior fascicular tachycardia. Initial echocardiogram revealed depressed ventricular function. The tachycardia was unresponsive to therapeutic trials of adenosine, esmolol, procainamide, and lidocaine. There was brief conversion of the tachycardia to sinus rhythm with transesophageal atrial overdrive pacing, suggesting a reentrant mechanism of the arrhythmia. Ultimately, the judicious administration of intravenous verapamil resulted in termination of the arrhythmia, which has been sustained on oral therapy.

Fascicular tachycardia in infancy and the use of verapamil: a case series and literature review

“…There are several reports of successful conversion of fascicular VT in young infants with intravenous verapamil 9–12 19. It is interesting to note that in none of these case reports verapamil was used as a first-line agent.…”

“…Nevertheless, calcium channel blockers are uniquely effective as the treatment of fascicular VT, to the point that this arrhythmia is also known as ‘verapamil sensitive ventricular tachycardia’. It typically occurs in children and young adults without structural heart disease 9–14. The underlying mechanism is believed to be a re-entry tachycardia involving the Purkinje fibres of the fascicles—typically the left posterior fascicle of the left bundle branch but also has features of an automatic tachycardia, can be incessant, unresponsive to direct current cardioversion and may lead to cardiomyopathy.…”

Case Report: Recurrent Left Posterior Fascicular Ventricular Tachycardia in a Newborn

“…Verapamil has recently been used for arrhythmia in infants ( 2 , 16 , 17 ). Slow intravenous infusion at a dose of 0.1 mg/kg over at least 10 min appeared to be safe and efficient in terminating infantile LPFVT, but only one newborn was enrolled ( 2 , 7 , 9 , 11 ).…”

Belhassen Tachycardia in a Pediatric Patient: A Simulation for Pediatric Emergency Medicine Fellows

“…Particular caution in infants is necessary as their immature myocardium poses an increased risk of verapamil-induced cardiovascular collapse. Intravenous calcium should be immediately administered in all cases to treat verapamil-induced hypotension [ 7 , 8 ].…”