Real-Time Integration of Intracardiac Echocardiography to Facilitate Atrial Tachycardia Ablation in a Patient With a Senning Baffle

Abstract

This case report concerns a 10-year-old boy who previously underwent a Senning operation for transposition of the great arteries with an intramural course of the coronary arteries. The patient had recurrent episodes of atrial tachycardia with 1:1 atrioventricular conduction that caused, in combination with dysfunction of the systemic right ventricle, hemodynamic instability. Unresponsive to antiarrhythmic drug treatment, the patient was referred to our institution for an electrophysiological study and radiofrequency catheter ablation. The procedure was performed under general anesthesia. Because the atrial tachycardia caused hemodynamic instability, the mapping procedure was aimed at identification of the arrhythmogenic substrate and critical isthmus of a presumed macro-reentrant circuit with only brief episodes of induced tachycardia. First, a registered 3D shell of the cardiac anatomy was created on an electroanatomic mapping system (Cartosound, Biosense Webster, Diamond Bar, Calif), using intracardiac echocardiography (ICE). By positioning the ICE catheter inside the systemic venous atrium, the entire cardiac anatomy could be visualized, including structures that form a potential area of conduction block such as the caval veins, the tricuspid valve annulus, and surgical suture lines (eg, atrial baffle suture line) (Figure 1). Second, bipolar voltage mapping of the systemic venous atrium was performed during sinus rhythm to further evaluate the …