Electroanatomic mapping and catheter ablation of atrial tachycardia originating from the tricuspid annulus

Abstract

We read with great interest with a recent case report from Cay et al. [1] published in International Journal of Cardiology. They reported an interesting case of successful radiofrequency ablation of idiopathic ventricular arrhythmia originating from the anterolateral free wall of tricuspid annulus (TA). We recently encountered a patient presenting with atrial tachycardia (AT) originating from the anterolateral free wall of the tricuspid annulus, who was successfully ablated using 3dimensional electroanatomic mapping system. A 62-year-old male patient was referred to our department for catheter ablation for symptomatic atrial tachycardia, which was resistant to metoprolol, propafenone, and amiodarone. He had a history of hypertension for 10 years. No underlying structural heart disease was detected by echocardiogram. P-wave morphology during tachycardia (Fig. 1) was “W” shape in the inferior leads, iso in lead I, and predominantly negative in lead V1, all suggesting the AT originating from the lateral free wall of the tricuspid annulus. During electrophysiologic study guided by the noncontact Ensite Array (EA) mapping system (St. Jude Medical, St. Paul, MN, USA), the tachycardia could be induced by atrial burst pacing. The cycle length of the tachycardia was 560 ms. The earliest atrial activation site during the arrhythmia was found near the anterolateral free wall of the TA (Movie). Activation mapping also showed the AT origin and its propagation to the other sites of the right atrium. Radiofrequency ablation using irrigated ablation catheter (Cool Path Ablation Catheter, St. Jude Medical) with average power of 30 W and maximum temperature of 43 °C at this site (Fig. 2) successfully terminated the tachycardia (Fig. 3), and AT was no longer inducible with and without isoproterenol infusion. The patient remained free from any atrial arrhythmias without anti-arrhythmic drugs during a follow-up period of one year. The focal atrial tachycardia originating from the TA is not commonly seen, and has been reported in separate cases [2–4] and case series [5,6] with an incidence of 9–10% of right atrial tachycardia. Furthermore, AT arising from the anterolateral free wall of the TA is relatively rare. Conventionally, intracardiac mapping of focal AT using 1 or 2 roving catheters was utilized to find the origin of AT. Noncontact mapping systems provide an accurate guidance for mapping and ablation of focal AT [7,8]. Supplementary data to this article can be found online at http:// dx.doi.org/10.1016/j.ijcard.2013.06.084. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology.