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.

No abstract

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 ...

Abyssomicin I (1), a new modified polycyclic polyketide, was isolated from the culture extract of a soil-derived Streptomyces sp. The structure of 1 was elucidated by interpretation of NMR and other spectroscopic data. The stereochemistry of the new compound was assigned by NOE analysis, chemical derivatization, and application of the modified Mosher method. While 1 was inactive against bacteria and yeasts, the oxidized derivative 7 showed weak activities against gram-positive bacteria. Compounds 1 and 7 exhibited inhibitory effects on tumor cell invasion with IC(50) values of 11 and 0.21 μM, respectively.

on behalf of the J-RHYTHM Registry Investigators* Background--To clarify the influence of hypertension and blood pressure (BP) control on thromboembolism and major hemorrhage in patients with nonvalvular atrial fibrillation, a post hoc analysis of the J-RHYTHM Registry was performed.

In the screening of antitumor compounds from microbial secondary metabolites, myxochelin A was isolated from a culture broth of Nonomuraea pusilla TP-A0861. The absolute configuration was determined to be S by synthesizing both enantiomers from an L-or D-lysine derivative and comparing their specific rotations. Both enantiomers of myxochelin A showed remarkable inhibitory effects on the invasion of murine colon 26-L5 carcinoma cells at non-cytotoxic concentrations. Keywords myxochelin A, invasion, antitumor, Nonomuraea IntroductionTumor invasion is the major cause of treatment failure and death in cancer patients. The process of invasion into the basement membrane is a cascade of sequential complex steps, mainly consisting of tumor cell adhesion, enzymatic degradation of extracellular matrix proteins, and migration [1]. Compounds that inhibit any of these steps are expected to be candidates of anti-metastatic and/or anti-invasive agents. Hence, the clinical efficacy of such invasive inhibitors in cancer chemotherapy are extensively exploited [2,3].In the screening for anti-invasive compounds from natural products, myxochelin A (1) was found to inhibit the in vitro tumor cell invasion. Herein, we describe the isolation, structure determination, synthesis and biological properties of 1. Results and Discussion Screening and Structure DeterminationThe screening method employed in this study is based on the experimental model of tumor cell invasion using Transwell cell culture chamber and Matrigel, the reconstituted basement membrane [4]. This bioassay enables the detection of compounds that inhibit cell adhesion, enzymatic degradation of extracellular matrix, or migration. While screening for anti-invasive compounds from our natural products library, significant activity was shown by myxochelin A (1, Fig. 1

Catheter ablation can eliminate both AF and prolonged sinus pauses in the majority of TBS patients. Nevertheless, such patients should be continuously followed-up, because gradual progression of sinus node dysfunction can occur after a long period of time.

Background Outcomes after sirolimus-eluting stent (SES: Cypher ® ) implantation remained to be elucidated in Japan. Methods and Results Among 1,070 consecutive angiographic follow-up lesions, 99 lesions underwent target lesion revascularization (TLR) with in-stent restenosis (ISR). Retrospective estimation by multivariate analysis including 50 variables showed that the ostiums of right coronary and left circumflex arteries, hemodialysis, calcification, non-direct stenting, ISR of SES, and non-eccentric lesion were the predictors of TLR. There was no documented late stent thrombosis (LST) among 2,166 lesions and very LST (VLST) among 1,423 lesions. Conclusion Further revises are needed to implant SES to these predictive lesions. LST and VLST were very rare. (Circ J 2007; 71: 1328 -1331