Right ventricular outflow tract resection for treatment of refractory ventricular tachycardia in a 2-year-old child

Abstract

Ventricular tachycardia (VT) of right ventricular origin in young children might be due to Purkinje cell tumors, arrhythmogenic right ventricular dysplasia (ARVD), or Uhl’s anomaly, or it might be idiopathic. Surgical intervention has been used in adults when medical or catheter ablative therapy is ineffective. We describe a unique cause of VT of right ventricular outflow tract (RVOT) origin in a young child that was successfully managed with surgical resection. Clinical Summary A 2-year-old child presented with syncope and near-incessant VT at a rate of 270 beats/min. The tachycardia was notable for subtle irregularities in both cycle length and QRS morphology (Figure 1). However, all QRS complexes suggested an RVOT origin, with positive vectors in leads II, III, and aVF. Transthoracic echocardiography showed marked dilation of the RVOT, which was confirmed by means of cardiac magnetic resonance imaging. At electrophysiologic testing, the arrhythmia could not be terminated with overdrive pacing but did temporarily stop with adenosine. Activation mapping defined the onset of activation at the anterior RVOT immediately inferior to the pulmonary valve annulus. Catheter probing of this area resulted in marked acceleration of the arrhythmia and hypotension. Because of the marked dilation and attenuation of tissue in this region and hemodynamic instability with mapping, catheter ablation was not performed. Despite pharmacologic therapy with amiodarone, lidocaine, and class 1C agents, recurrences of sustained VT with hemodynamic compromise persisted. Thus surgical intervention was recommended, with anticipation that discrete myocardial tumors would be identified. At the time of the operation, the anterior free wall of the RVOT was dilated and visibly thin, and it collapsed when the patient was From the Department of Cardiothoracic Surgery, Children’s Hospital of Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, Calif.