The use of additional RF applications to eliminate transient PV reconnection induced by ATP injection led to a reduction of AF recurrence after PVI, most likely due to the minimization of the subsequent PV reconnection.

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 ...

atients with congestive heart failure (CHF) are frequently re-hospitalized, worsening their quality of life, and re-hospitalization for CHF is also associated with increased mortality rates. 1,2 Therefore, re-hospitalization for CHF should be avoided. Renal insufficiency increases the risk of CHF, [3][4][5] but most studies that have investigated the role of renal function in CHF have included only subjects with no known CHF or mild-to-moderate CHF and excluded patients with severe renal dysfunction. Patients hospitalized for CHF have more severe disease and impaired renal function, but little is known about the relation between renal dysfunction and re-hospitalization because of CHF. Thus, the aim of the present study was to investigate whether renal dysfunction is associated with rehospitalization for CHF after successful discharge. MethodsThe study protocol was approved by the Ethics Committee of The Jikei University School of ).Patients with CHF who had been admitted from January 2003 through December 2004 and followed up after discharge at the outpatient clinic were reviewed. CHF was diagnosed by 2 or more cardiologists on the basis of the Framingham criteria. Patients were excluded if they had CHF complicated by acute myocardial infarction, were undergoing or starting dialysis during the follow-up period, or had undergone cardiac surgery during the follow-up period. With these selection criteria, 109 patients were enrolled. The duration of follow-up was 6-1,466 days (mean, 496 days; median, 348 days). The estimated glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease equation 6 coefficient modified for Japanese patients: estimated GFR = 0.741×175× Cr -1.154 × age -0.203 (ml · min -1 · 1.73 m -2 ). For women, the estimated GFR was multiplied by a correction factor of 0.742.The 109 patients were divided into 2 groups: decreased renal function (estimated GFR on admission <45 ml·min -1 · 1.73 m -2 ; 42 patients) and preserved renal function (estimated GFR on admission ≥45 ml·min -1 ·1.73 m -2 ; 67 patients). The 2 groups were compared on the basis of age, sex, New York Heart Association (NYHA) class on admission, prescribed anti-CHF drugs at discharge, and the rates of coronary artery disease, valvular heart disease, cardiomyopathy, atrial fibrillation, hypertension, diabetes mellitus (DM), dyslipidemia, anemia, systolic dysfunction, previous hospitalization for CHF, and worsening renal function during hospitalization. Cardiomyopathy was defined according to heart catheterization or previous diagnosis. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or previous history. DM was defined as fasting plasma glucose concentration ≥126 mg/dl, Background Patients with congestive heart failure (CHF) are often re-hospitalized, worsening both their quality of life and prognosis. Although renal dysfunction reportedly increases the risk of CHF, the association between renal dysfunction and re-hospitalization for CHF remains unclear...

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The excitation of cardiac muscle tissue, which has migrated to the pulmonary veins, was thus found to play an important role in the formation of the middle part of the P wave/loop.