心房迷宫式射频消融治疗心房颤动

目的：探讨经心外膜迷宫式射频消融心房治疗心房颤动（房颤）的可行性。方法：对６例风湿性心脏病合并房颤患者〔持续性房颤史３．３±２．７年，左心房直径３４．７±５．３ｍｍ，心功能（ＮＹＨＡ分级）Ⅱ～Ⅳ级〕，在瓣膜置换或分离术后继续在开胸状态下分别环形消融左右心耳根部及其间横窦、上下腔静脉之间及右房前壁和冠状窦。结果：６例患者术后均恢复窦性心律。平均射频消融加瓣膜手术时间为３．０±０．７小时。无一例术中及术后发生心房穿孔或Ⅲ度房室传导阻滞。心功能较术前显著改善（Ｐ＜０．０５）。术后随访１２～２０个月，除１例患者于第８个月恢复房颤外，余均维持窦性心律。结论：本方法可以达到治疗房颤的目的。     

High‐Density Lipoprotein: A Novel Target for Antirestenosis Therapy

Restenosis is an integral pathological process central to the recurrent vessel narrowing after interventional procedures. Although the mechanisms for restenosis are diverse in different pathological conditions, endothelial dysfunction, inflammation, vascular smooth muscle cell (SMC) proliferation, and myofibroblasts transition have been thought to play crucial role in the development of restenosis. Indeed, there is an inverse relationship between high‐density lipoprotein (HDL) levels and risk for coronary heart disease (CHD). However, relatively studies on the direct assessment of HDL effect on restenosis are limited. In addition to involvement in the cholesterol reverse transport, many vascular protective effects of HDL, including protection of endothelium, antiinflammation, antithrombus actions, inhibition of SMC proliferation, and regulation by adventitial effects may contribute to the inhibition of restenosis, though the exact relationships between HDL and restenosis remain to be elucidated. This review summarizes the vascular protective effects of HDL, emphasizing the potential role of HDL in intimal hyperplasia and vascular remodeling, which may provide novel prophylactic and therapeutic strategies for antirestenosis.     

Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.     

Electrophysiological Effect of the Maze Procedure on Canine Sinoatrial Node Function

The maze procedure is an operation that has had great initial success in curing atrial fibrillation. This procedure includes several right atrial incisions that may interrupt the integrity of the sinoatrial node or its arterial supply. To assess the effect of the maze procedure on sinus node function (SNF), the following studies were performed: sinus node recovery times (SNRT), corrected SNRT (CSNRT), CSNRT under autonomic blockade maximal heart rate and intrinsic heart rates. Thirty-four dogs underwent a right thoracotomy with cardiopulmonary bypass (CPB). The dogs were divided into three groups. Group I (n = 9), the sham group, underwent CPB without any incisions. Group 2 (n = 8) underwent CPB and one of the right atria] incisions. Group 3 (n = 18) underwent CPB and all three of the right atrial incisions. SNF was determined before and after the procedure. Groups 1 and 2 had no significant difference in measured SNF acutely after the procedure. In Group 3 the mean SNRT increased from 552 msec to 1,984 msec (P = 0.005). Sinus node dysfunction was corroborated by all studies. In the chronic studies, a trend toward recovery of SNF was observed. The maze procedure results in significant acute sinus node dysfunction. This dysfunction may resolve spontaneously over the ensuing months. Modifications of the maze procedure that avoid the sinus node or its blood supply area may reduce procedure related sinus node dysfunction.