Focal Left Atrial Tachycardias Not Associated with Prior Catheter Ablation for Atrial Fibrillation: Clinical and Electrophysiological Characteristics

Background: The clinical features and electrophysiological characteristics of patients with focal left atrial tachycardias (LATs) are not well characterized. This study reports the experience of a single center in catheter mapping and radiofrequency ablation of focal LAT not associated with prior atrial fibrillation (AF) ablation, including in cardiac sarcoidosis and transplant patients. Methods: Patients with focal LAT without a history of AF ablation were included in this retrospective analysis. Results: A total of 24 focal LATs were documented in 20 patients. Two patients were subsequently diagnosed with cardiac sarcoidosis. Two patients were status post a thoracic transplant. The mean initial cycle length of the focal LATs was 347.4 +/- 96.2 ms (range 190-510 ms). Patients with a pulmonary vein (PV) ostium focus (n = 6) demonstrated a shorter cycle length than patients with other LA foci (259.2 +/- 56.4 ms vs 371.9 +/- 91.1 ms, P = 0.02), as well as a trend for a history of AF (67% vs 21%, P = NS). Catheter ablation was immediately successful for 19 of 22 focal LATs. Conclusions: Focal LATs not associated with prior AF ablation can originate in a variety of LA locations and clinical settings. Focal LAT arising in the PV ostia is associated with a history of AF and demonstrates a faster tachycardia rate. We also report focal LAT in cardiac sarcoidosis patients and in the donor heart of an orthotopic heart transplant recipient. Radiofrequency ablation is a successful treatment for focal LAT not associated with prior ablation, including those refractory to medical therapy. (PACE 2012; 35: 17-27)