Preferential Conduction Properties Along The Left Lateral Ridge And The Arrhythmogenicity Of The Left Pulmonary Veins In Patients With Atrial Fibrillation.

PURPOSE:In this study, we examined the hypothesis that the preferential conduction property along left lateral ridge (LLR) might affect the arrhythmogenicity of left pulmonary veins (LPVs). METHODS:The study population included 40 consecutive AF patients. Radiofrequency energy (RF) was sequentially delivered along the LLR from a lower to upper manner during postero-lateral CS pacing during an isoproterenol infusion. RESULTS:The conduction time during pacing from the CS was significantly prolonged during radiofrequency (RF) deliveries (before vs. after, upper; 91±26ms vs. 127±38ms, p<0.001, lower; 86±21ms vs. 103±22ms, p<0.001). Remarkable prolongation of more than 30ms was observed in 19 of 40 patients (48%) (both LPVs, 6; only the upper LPVs, 12; and only the lower LPV, 1). Sites with a remarkable prolongation were observed at the carina between the LPVs,[4] anterior site of the upper LPV carina,[10] anterior wall of the lower LPV,[3] and bottom of the lower LPVs [2] Thirty-three arrhythmogenic foci (AMF) from the LPVs were observed in 23/40 patients (56%). The conduction time during pacing from the LPVs during the RF delivery was significantly longer in the patients with AMF from the upper LPV than in those patients without (107±36ms vs. 146±40ms, p<0.01). CONCLUSION:The LLR includes the preferential conduction properties between the CS and LPVs, and the observation of the serial changes during the RF delivery could provide us information about the LPVs arrhythmogenicity.