The Importance of Typical Atrial Flutter in Patients with Repaired Congenital Heart Disease and Intra-Atrial Reentrant Tachycardia

Background: The ablation for intra-atrial reentrant tachycardias (IART) in congenital heart disease (CHD) remains difficult. Methods: Electrophysiologic and electroanatomic mapping data and acute outcomes were reviewed in postoperative patients with congenital heart disease who underwent electrophysiologic study/radiofrequency Catheter ablation between January 2005 and February 2011. The study included 13 patients (10 male, 42±12 years) with CHD and IART. They had undergone operation for ASD (n=6), VSD (n=2), TOF (n=4), and pulmonary atresia (n=1). Results: Among total 15 IARTs which were mapped, 10 and 5 IARTs were typical and atypical atrial flutter, respectively. Atypical flutter included IART involving the isthmus between the right atriotomy scar and the inferior vena cava (n=2), and scar-related IART (n=3). Typical atrial flutter (273.2±42.7 msec) had longer cycle length than atypical flutter (227.2±25.8 msec, p=0.027). However, sawtooth appearance in inferior leads and positive P wave in lead V1 were observed in only 5 out of 10 typical atrial flutter. Ablation was performed with conventional mapping and electroanatomic mapping in 10 and 3 patients, respectively. The acute success rate was 92.3% and the recurrence rate was 15.4% during a follow-up of 34 months. Conclusions: Typical atrial flutter was the most common IART in patients with repaired CHD and had longer cycle length than atypical flutter, and easily manageable by Catheter ablation.