Pulmonary vein isolation combined with superior vena cava isolation for atrial fibrillation ablation: a prospective randomized study
ABSTRACT Circumferential pulmonary vein isolation (CPVI) is an established strategy for atrial fibrillation (AF) ablation. Superior vena cava (SVC), by harbouring the majority of non-pulmonary vein (PV) foci, is the most common non-PV origin for AF. However, it is unknown whether CPVI combined with SVC isolation (SVCI) could improve clinical results and whether SVCI is technically safe and feasible.
A total of 106 cases (58 males, average age 66.0 +/- 8.8 years) with paroxysmal AF were included for ablation. They were allocated randomly to two groups: CPVI group (n = 54) and CPVI + SVCI group (n = 52). All cases underwent the procedure successfully. Pulmonary vein isolation was achieved in all cases. The procedural time and fluoroscopic time were comparable between the two groups. The mean ablation time for SVC was 7.8 +/- 2.7 min. Superior vena cava isolation was obtained in 50/52 cases. In the remaining two cases, SVCI was not achieved because of obviating diaphragmatic nerve injury. During a mean follow-up of 4 +/- 2 months, 12 (22.2%) cases in the CPVI group and 10 (19.2%) cases in the CPVI + SVCI group had atrial tachyarrhythmias (ATa) recurrence (P = 0.70). Nine of 12 cases in the CPVI group and 8/10 cases in the CPVI + SVCI group underwent reablation (P = 0.86), and PV reconnection occurred in 7/9 cases in the CPVI group and in 8/8 cases in the CPVI + SVCI group. All PV reconnection was reisolated by gaps ablation. There was no SVC reconnection in the CPVI + SVCI group. In two cases without PV reconnection from the CPVI group, SVC-originated short run of atrial tachycardia was identified and eliminated by the SVCI. At the end of 12 months of follow-up, 50 cases (92.6%) in the CPVI group and 49 (94.2%) in the CPVI + SVC group were free of ATa recurrence (P = 0.73).
In our series of paroxysmal AF patients, empirically adding SVCI to CPVI did not significantly reduce the AF recurrence after ablation. Superior vena cava isolation may be useful, however, in selected patients in whom the SVC is identified as a trigger for AF. However, because of the preliminary property of the study and its relatively small sample size, the impact of SVCI on clinical results should be evaluated in a large series of patients.
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ABSTRACT: Abstract Purpose: The aim of this study is to investigate the effects of ablation parameters on thermal distribution during microwave atrial fibrillation catheter ablation, such as ablation time, ablation power, blood condition and antenna placement, and give proper ablative parameters to realise transmural ablation. Materials and methods: In this paper, simplified 3D antenna-myocardium-blood finite element method models were built to simulate the endocardial ablation operation. Thermal distribution was obtained based on the coupled electromagnetic-thermal analysis. Under different antenna placement conditions and different microwave power inputs within 60 s, the lesion dimensions (maximum depth, maximum width) of the ablation zones were analysed. Results: The ablation width and depth increased with the ablation time. The increase rate significantly slowed down after 10 s. The maximum temperature was located in 1 mm under the antenna tip when perpendicular to the endocardium, while 1.5 mm away from the antenna axis and 26 mm along the antenna (with antenna length about 30 mm) in the myocardium when parallel to the endocardium. The maximum temperature in the ablated area decreased and the effective ablation area (with the temperature raised to 50°C) shifted deeper into the myocardium due to the blood cooling. Conclusion: The research validated that the microwave antenna can provide continuous long and linear lesions for the treatment of atrial fibrillation. The dimensions of the created lesion widths were all larger than those of the depths. It is easy for the microwave antenna to produce transmural lesions for an atrial wall thickness of 2-6 mm by adjusting the applied power and ablation time.International Journal of Hyperthermia 07/2013; DOI:10.3109/02656736.2013.803606 · 2.77 Impact Factor
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ABSTRACT: PURPOSE OF REVIEW: Superior vena cava (SVC) is one of the most important nonpulmonary vein origins of atrial fibrillation, and SVC should be carefully treated in order to decrease the recurrence of atrial fibrillation after ablation. Despite the fact that pulmonary vein isolation (PVI) should be performed prophylactically for all pulmonary veins, prophylactic SVC isolation (SVCI) is still controversial. This review describes recent data on treatments for SVC focus during atrial fibrillation ablation. RECENT FINDINGS: There are two different major approaches to treat SVC focus during atrial fibrillation ablation. One is the conventional approach, in which SVCI is performed only if atrial fibrillation from SVC origin is recognized using pacing maneuvers and/or isoproterenol infusions. Another approach is performing SVCI in all cases prophylactically in addition to PVI. The rate of atrial fibrillation freedom 1 year after initial atrial fibrillation ablation by prophylactic PVI along with SVCI was almost the same as with the conventional method (85-90% atrial fibrillation freedom). In addition, the conventional method also had a good result even 5 years after ablation (73.3%). SUMMARY: Because of the good result after using the conventional approach and possible complications during SVCI, SVCI should be performed only if SVC focus is recognized, not prophylactically.Current opinion in cardiology 11/2012; DOI:10.1097/HCO.0b013e32835b099b · 2.59 Impact Factor
Heart, Lung and Circulation 01/2011; 20. DOI:10.1016/j.hlc.2011.05.229 · 1.17 Impact Factor