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.