Verdino Ralph J
Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA.
J Electrocardiol. 2006 Oct;39(4 Suppl):S184-7. doi: 10.1016/j.jelectrocard.2006.05.010. Epub 2006 Aug 28.
The surgical approach to treat atrial fibrillation involves compartmentalizing the atrium. By dividing the atrium into discrete segments, the surgeon prevents the arrhythmia's ability to sustain by decreasing the required atrial substrate for propagation of the fibrillatory wavelets. Endocardial catheter ablation techniques used to replicate the surgical procedure were fraught with long procedure times and unacceptably high thromboembolic complications. The realization that the initiation of atrial fibrillation is often caused by triggers within the pulmonary veins has changed the focus from preventing the arrhythmia's ability to maintain itself to preventing the arrhythmia from ever being initiated. Early focal catheter ablation of atrial fibrillation used activation mapping and pace mapping to identify sites of spontaneous firing that led to bursts of atrial fibrillation. Although acute success rates were quite high, recurrences were unacceptably common. When investigators reattempted ablation of these patients, triggers were often found in other areas of the vein initially targeted and/or in remote veins. Because it appeared that either new triggers could arise in nonablated areas of veins or these areas were arrhythmogenic but not realized during initial ablation, the technique of complete isolation of the pulmonary vein was developed. A circular mapping catheter was placed at the funnel-shaped opening of each vein to map electrical exit sites of the vein into the atrium. Early attempts at electrical isolation of the veins occasionally caused pulmonary vein stenosis, on occasion necessitating angioplasty or stenting of the vein. This phenomenon has caused investigators to isolate the veins by using much larger circles with far greater diameters along the posterior left atrium. Many investigators now also have added ablation lines along the roof of the left atrium as well as down to the mitral valve annulus. The technique appears to be more analogous to the surgical model, now isolating triggers as well as preventing arrhythmia propagation.
治疗心房颤动的手术方法包括将心房分隔开来。通过将心房划分为离散的节段，外科医生可通过减少颤动小波传播所需的心房基质来阻止心律失常的持续。用于复制该手术过程的心内膜导管消融技术存在手术时间长和血栓栓塞并发症高得难以接受的问题。认识到心房颤动的起始通常由肺静脉内的触发因素引起，已将重点从阻止心律失常维持自身的能力转变为防止心律失常的起始。早期的心房颤动局灶性导管消融使用激动标测和起搏标测来识别导致心房颤动发作的自发放电部位。尽管急性成功率相当高，但复发却极为常见。当研究人员再次尝试对这些患者进行消融时，触发因素常常在最初靶向的静脉的其他区域和/或远处的静脉中被发现。因为似乎要么新的触发因素会在静脉的未消融区域出现，要么这些区域具有致心律失常性但在初次消融时未被发现，所以发展出了肺静脉完全隔离技术。将环形标测导管放置在每条静脉的漏斗形开口处，以标测静脉进入心房的电出口部位。早期对静脉进行电隔离的尝试偶尔会导致肺静脉狭窄，有时需要对静脉进行血管成形术或置入支架。这种现象促使研究人员沿着左心房后壁使用直径大得多的更大的环来隔离静脉。现在许多研究人员还在左心房顶部以及向下至二尖瓣环处添加了消融线。该技术似乎更类似于手术模型，现在既能隔离触发因素又能防止心律失常的传播。
