Lasso catheter guided ablation for paroxysmal atrial fibrillation: The first experience in Thailand

The authors used the 10-pole pulmonary vein sized loop-shaped, lasso, catheter via a transatial septal long sheath in 10 patients who had symptomatic refractory paroxysmal atrial fibrillation (PAF) in order to map and guide for catheter ablation. The radiofrequency current was delivered at the junction between atrial tissue and the pulmonary vein which was the earliest endocardial activation time of the premature atrial contraction (PAC) initiating the PAF and at the pulmonary vein potential during sinus rhythm. Twenty two foci of PAC, 10 and 7, 4 and 1 from left and right superior and left and right inferior pulmonary veins, respectively, and 5 pulmonary vein potentials, 2 and 3 from left and right superior pulmonary veins, respectively, were ablated. After AF ablation, classical atrial flutter (AF1) could be induced in 9 patients. Isthmus line of block for AF1 was performed in all patients. Two patients had atrial tachycardia at the high right atrium and also successfully ablated. The mean fluoroscopic and procedure times were 87 and 300 minutes, respectively. One patient had deep vein thrombosis which resolved after anticoagulant therapy. One patient had recurrent PAF which was successfully reablated but he still had very mild symptoms. During the mean follow-up period of 5.8 months, 9 patients remained free of symptoms. Conclusion: Lasso catheter is an effective tool for mapping and guiding of ablation for PAF. However, more experience and long-term follow-up are required.