Transesophageal echocardiography for thrombus screening prior to left atrial catheter ablation.

BACKGROUND: Transesophageal echocardiography (TEE) is useful for detecting left atrial (LA) thrombus prior to percutaneous LA catheter ablation in patients with atrial fibrillation (AF). This study was designed to evaluate clinical predictors of LA thrombus and determine indications for TEE screening prior to LA ablation. METHODS AND RESULTS: The study consisted of 446 patients with drug-resistant AF who were scheduled to undergo initial LA ablation (age 59+/-11 years, 312 males, 136 persistent AF). TEE was performed in all cases within 24 h before ablation. We assessed clinical parameters including CHADS(2) score and echocardiographic parameters. LA thrombus was detected in 13 cases (2.9%) prior to LA ablation (67+/-8 years, 10 males, 12 persistent AF). In multiple logistic regression analysis, advanced age (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0-1.2; P<0.05), persistent AF (OR 38.1, 95%CI 1.4-988; P<0.05) and structural heart diseases (OR 29.8, 95%CI 2.8-383; P<0.01) were independent positive predictors of LA thrombus prior to ablation, while CHADS(2) score and LA volume were not significant predictors. None of the 136 patients with paroxysmal lone AF whose age was below 60 years had LA thrombus prior to ablation. CONCLUSIONS: It might be reasonable to omit TEE as a screening examination for LA thrombus prior to LA ablation in younger paroxysmal lone AF patients.

ATP-induced dormant pulmonary veins originating from the carina region after circumferential pulmonary vein isolation of atrial fibrillation.

INTRODUCTION: Elimination of transient pulmonary vein recurrences (dormant PVs) induced by an ATP injection and ablation at the PV carina region is an effective strategy for atrial fibrillation (AF) ablation. The relationship between dormant PVs and the PV carina region has not been evaluated. METHODS: A total of 212 consecutive symptomatic AF patients underwent circumferential PV electrical isolation (CPVEI) with a double lasso technique. They were divided into 2 groups in a retrospective review; Group 1: those given an ATP injection during an intravenous isoproterenol infusion after the CPVEI (n = 106), and Group 2: those in which it was not given after the CPVEI (n = 106). Radiofrequency energy was applied at the earliest dormant PV activation site identified using a Lasso catheter on the CPVEI line and then PV carina region if it was ineffective. RESULTS: After a successful PVEI, 54 patients (51%) in Group 1 had PV reconnections during an ATP injection. Acute PVEI sites were observed on the carina region within the CPVEI line in the right PVs (16%) and left PVs (10%). Dormant PVs were reisolated at the carina region in the right PVs (23%) and left PVs (26%). The distribution of the dormant PV sites, except for the RIPV, significantly differed from that of the acute PVEI sites (P < 0.05). Further, AF recurred significantly in the Group 2 patients as compared to those in Group 1 during 16 +/- 6.1 months of follow-up (P < 0.05). CONCLUSION: PV carina region origins may partly be responsible for an acute PVEI and potential recurrences.