Study of underlying mechanism of chronic atrial fibrillation and development of new less invasive surgery

为探讨慢性心房颤动（简称房颤）合并瓣膜病的电生理特点，采用多点电极和特制标测系统，在心房表面标测房颤的电活动。数据主要采集自两个心房的心房游离壁和解剖障碍物，如肺静脉口，并使用专门设计的软件进行分析。本研究未发现“大折返”现象，但发现了其他新的传播模式。这些结果表明，早期激动从左心房发生并传播到右心房，从而由于右心房不应期不等而在右心房形成混乱的激动模式。我们根据这些电生理发现开发了一种新的、更简单的外科手术方法，命名为“肺静脉口隔离术”。为了消除慢性心房颤动，我们进行了与二尖瓣手术相关的手术，并成功地将这些患者设置为术后心房颤动，然后，超过80%的患者术后无心房颤动。左房内径大、术前房颤持续时间长是房颤复发的预测因素。两房电生理状态的微小差异也可预测术后结局。超声心动图检查显示，恢复窦性心律的患者术后心脏功能良好，大多数患者在二尖瓣血流中观察到左心房踢血。

To examine the electrophysiological characteristics of chronic atrial fibrillation associated with valvular disease, electrical activity of atrial fibrillation was mapped on the atrial surface by means of multi-point electrodes and specially made mapping system. Data were mainly acquired from the atrial free wall of both atria and anatomical obstacles, such as the orifice of pulmonary veins, and were analyzed using specially designed software. In this study, "macroreentry" was not detected but other new propagation patterns were found. Using spectral analysis, electrophysiological difference was noted between both atria. These findings suggest that early activation occurred from the left atrium and propagated to the right atrium and thus chaotic activation pattern was formed in the right atrium because of unequal refractory period on the right atrium.We developed a new, more simple surgical procedure, named as "pulmonary vein orifice isolation procedure", based on these electrophysiological findings. To eliminate chronic atrial fibrillation, we performed this procedure associated with mitral valve surgery and successfully set these patients, then, more than 80% of these free from atrial fibrillation postoperatively. Large left atrial dimension and long duration of preoperative atrial fibrillation was the predictive factor for the recurring atrial fibrillation. Small difference of electrophysiological status in both atria also predicted postoperative outcome. From the echocardiographic examination, posloperative cardiac performance was excellent in those cases who regained sinus rhythm and left atrial kick in the transmitral flow was observed in the majority of those patients.