Conduction Recovery After Pulmonary Vein Isolation for Atrial Fibrillation

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp hyroid dysfunction, especially hyperthyroidism, is frequently associated with the development of atrial fibrillation (AF) and the prevalence of AF in patients with hyperthyroidism is significantly higher than that in euthyroid subjects. 1-3 A previous study reported that the incidence of AF was 2.3% in patients with normal levels of serum thyroid-stimulating hormone (TSH), but increased to 13.8% in patients with hyperthyroidism. 1 Even in patients with subclinical hyperthyroidism, a 5-fold increase in the risk of AF was observed. 1 According to the recent guideline, restoring to euthyroid and rate control were recommended for patients with hyperthyroidism-related AF. 4 In our previous study of patients with hyperthyroidism-related AF who had been euthyroid for more than 3 months, catheter ablation of AF guided by a 3-D mapping system was a therapeutic option. 5 However, the impact of thyroid function on the recurrence rate was not determined according to thyroid function stratification was a limitation of the study. A crosssectional population-based study showed that the serum free thyroxine (FT4) concentration was independently associated with AF, even in euthyroid persons with TSH levels in the normal range. 3 Because most of the AF pathogenic factors present in patients with high levels of FT4 remain even after ablation, it is reasonable to hypothesize that FT4 at a highnormal level increases the risk of recurrence of AF after catheter ablation, so we conducted a prospective study to test this hypothesis. Methods Study SubjectsConsecutive patients with refractory symptomatic paroxysmal AF who were hospitalized in Beijing An Zhen Hospital (affiliated to Capital Medical University) for index circumferential pulmonary vein (PV) radiofrequency ablation from January 2006 to November 2007 were prospectively enrolled. Exclusion criteria included thyroid dysfunction on admission (abnormal level of FT4 or TSH), prior thyroid dysfunc-

Section: Study Limitationsmentioning

confidence: 56%

High-Normal Thyroid Function and Risk of Recurrence of Atrial Fibrillation After Catheter Ablation

Tang

Liu

Dong

et al. 2010

“…Although PV isolation is an effective therapy, in prior studies a large percentage of patients required additional ablation procedures. [3][4][5]7 In the present patients who underwent a second procedure, recovery of conduction through the surrounding PVs was the most common reason for recurrent AF after PV isolation. As the recovered LA-PV conduction is weak, antiarrhythmic drugs with a depressant effect on conduction properties may create a LA-PV conduction block.…”

Section: Hybrid Therapy With Pilsicainide and Pv Isolationmentioning

confidence: 69%

“…[3][4][5] It has been reported that PV isolation can result in a significant reduction in the severity of symptoms and can improve the QOL of patients with drug-refractory paroxysmal AF (PAF); 6 however, in prior studies of PV isolation, the recurrence rate has been relatively high and a repeat ablation procedure is sometimes required. [3][4][5]7 In some cases of unsuccessful ablation, antiarrhythmic agents that were ineffective before the ablation may become effective, but the mechanisms of hybrid therapy with antiarrhythmic agents and PV isolation are unclear. Therefore, we assessed the efficacy of hybrid therapy with a pure Na + channel blocker, pilsicainide, and PV isolation for PAF.…”

mentioning

confidence: 99%

Hybrid Therapy With Pilsicainide and Pulmonary Vein Isolation for Atrial Fibrillation

Tojo

Kumagai

Noguchi

et al. 2005

Self Cite

, are widely used for pharmacologic cardioversion and prevention of atrial fibrillation (AF); 1,2 however, if they are ineffective, radiofrequency catheter ablation targeting the pulmonary veins (PV) can be used to cure AF. [3][4][5] It has been reported that PV isolation can result in a significant reduction in the severity of symptoms and can improve the QOL of patients with drug-refractory paroxysmal AF (PAF); 6 however, in prior studies of PV isolation, the recurrence rate has been relatively high and a repeat ablation procedure is sometimes required. [3][4][5]7 In some cases of unsuccessful ablation, antiarrhythmic agents that were ineffective before the ablation may become effective, but the mechanisms of hybrid therapy with antiarrhythmic agents and PV isolation are unclear. Therefore, we assessed the efficacy of hybrid therapy with a pure Na + channel blocker, pilsicainide, and PV isolation for PAF. Methods PatientsThe study population consisted of 74 patients (54 men, 20 women; mean age, 56±6 years) with symptomatic drugrefractory PAF who were referred for an electrophysiological study and catheter ablation. A mean of 3.0±1.0 antiarrhythmic drugs, including pilsicainide, had been Circulation Journal Vol.69, December 2005 administered unsuccessfully. None had been treated with amiodarone during the preceding 6 months. The patients had frequent episodes of PAF, frequent atrial premature beats documented by 24-h Holter monitoring, or spontaneous re-initiation of AF after defibrillation. Fifteen patients had additional cardiovascular diagnoses, including systemic hypertension in 13 and ischemic heart disease in 2. Electrophysiological StudyWritten informed consent was given by all patients. Antiarrhythmic drugs were discontinued 5 half-lives before ablation. Treatment with anticoagulants, which were taken by all of the patients, was stopped on admission. Three 6-French quadripolar electrode catheters (Daig) were placed in the right atrial appendage, His bundle area and coronary sinus. A transseptal approach was performed with an 8.5rF long sheath, both for the puncture and to introduce a 31 mm, 64-pole basket catheter (EP Technologies) dedicated to PV mapping. A 4-mm-tip conventional ablation catheter (EP Technologies) was also introduced into the left atrial (LA) for ablation. PV angiography was performed with an angiocatheter (6-Fr, Baxter) to determine the position of the basket catheter relative to the ostium of the PV. The proximal electrode (bipoles 7-8) of the basket catheter was located at the PV-LA junction. The proximal part of the PV was defined as the ostial side of the veins, and the distal was referred to as the lung side.In patients with recurrence of AF, a second session was performed. The electrophysiological study was performed to assess the effect of pilsicainide on the electrophysiological properties of PV before ablation. PV pacing was performed from the distal (bipoles 1-2) electrode pair of all splines of the basket catheter. A programmed stimulator Background Pulmonary vein (PV) isol...

“…Because it is now well recognized that resumption of conduction in previously isolated PVs can occur in most cases with AF recurrence and that re-isolation of these PVs leads to marked improvement in ablation outcome, [26][27][28] repeat procedures might be regarded as a part of a stepwise approach to more complete isolation of targeted PVs.…”

Section: Discussionmentioning

confidence: 99%

Segmental Pulmonary Vein Antrum Isolation Using the "Large-Size" Lasso Catheter in Patients With Atrial Fibrillation

Yamane

Date

Kanzaki

et al. 2007

lthough the efficiency of ostial pulmonary vein isolation (OPVI) to suppress the occurrence of atrial fibrillation (AF) is well established, 1 the relatively frequent recurrence of AF 2 and the appearance of pulmonary vein (PV) stenosis 3 have recently been highlighted as major limitations of this approach. Because the isolation of the PVs, together with their surrounding tissue, might overcome these problems, at least in part, several approaches using linear ablation techniques, such as circumferential linear ablation using electroanatomical mapping 4 or circumferential 2×2 PV isolation (PVI), 5 have so far been developed; however, there have only been a few reports describing the effects of segmental radiofrequency (RF) application outside the PV ostium. 6 In this report, we describe the feasibility and efficiency of performing segmental PV antrum isolation (PVAI) using large-sized Lasso catheters compared with the conventional OPVI method. Methods Patient PopulationThis study included 187 consecutive patients who underwent PV mapping and ablation for multidrug-resistant AF (paroxysmal AF: 120 patients; persistent AF: 67 patients) and thereafter were observed for at least 12 months Circulation Journal Vol.71, May 2007 (Table 1). We defined persistent AF as an episode of AF that lasted for more than 14 days and required cardioversion to restore sinus rhythm (SR). Cases of long-lasting persistent AF for more than 12 months were not included. The study group comprised 144 males and 43 females with a mean age of 55±8 years. Forty-five patients had evidence of cardiovascular diseases: 32 had hypertension, 9 had coronary artery disease, 5 had dilated cardiomyopathy, and 3 had mitral valve regurgitation. Two types of mapping and ablation techniques were used for PVI. In Group 1, which comprised the first 70 consecutive patients (52 males, mean age: 52.0±10.3 years), each PV was disconnected from the left atrium (LA) at its ostium. In Group 2, which included the subsequent 117 patients (92 males, mean age: 53.2±9.8 years), PVI was performed at its antrum, targeting not only the PV itself but also the surrounding tissues. All patients underwent the ablation procedure and subsequent observaCirc J 2007; 71: 753 -760 (Received October 20, 2006; revised manuscript received January 24, 2007; accepted February 22, 2007 Background The limited efficacy and complications of segmental ostial pulmonary vein isolation (PVI) for treating atrial fibrillation (AF) have been discussed so, in the present study the feasibility and efficiency of performing segmental pulmonary vein (PV) antrum isolation to treat AF were assessed. Methods and Results A total of 187 patients with drug-refractory AF (paroxysmal 120, persistent 67) underwent segmental PVI guided by circumferential 20-electrode catheters (Lasso). Radiofrequency (RF) current was delivered either at the ostium using a regular Lasso (15-20 mm in diameter, 70 patients: Group 1) or at the antrum using a larger Lasso (25-30 mm in diameter, 117 patients: Group 2). A significantly ...