Atrial flutter after lateral tunnel construction in the modified Fontan operation: a canine model.
Atrial flutter after lateral tunnel construction in the modified Fontan operation: a canine model.
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改良 Fontan 手术中侧向隧道构建后的心房扑动：犬模型。
DOI：
10.1016/s0022-5223(96)70303-3
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Huddleston,CB
中科院分区：
文献类型：
--
作者：
Rodefeld,MD;Bromberg,BI;Schuessler,RB;Boineau,JP;Cox,JL;Huddleston,CB
房内折返性心动过速或房扑是Fontan修复术后常见的问题，涉及心房连接。Fontan修补术的改良，全腔静脉连接，使暴露于牵张和高血压的右心房部分最小化;然而，房扑在该手术后继续发生。我们推测，在没有心房高压或牵张等生理改变的情况下，全腔静脉连接的心房内外侧隧道缝合线为心房扑动提供了必要的电生理学基础。本研究的目的是建立犬全腔静脉连接模型（1）以确定单独的心房内缝合线足以允许持续性房扑和（2）表征导致折返性心律失常的途径。全身麻醉诱导后，对25至30公斤的狗（n = 17）进行正中胸骨切开术、心包支架并在右心耳上放置起搏电极。开始常温心肺转流。通过标准右心房切开术放置全腔静脉连接缝合线，模拟侧向隧道的构建。关闭心房切口后，通过双侧心室切开术放置253点单极心房内电极形状拟合电极。通过心房短阵起搏和程序性超刺激，尝试诱发心房扑动。如果不能诱发心房扑动，则输注异丙肾上腺素并重复刺激方案。诱导心房扑动后，进行激动序列标测。在缝合线放置前，没有犬发生可诱导的房扑。放置缝合线后，每只狗都可重复诱导持续性房扑，尽管其中三只狗（17.6%）需要异丙肾上腺素。平均扑动周期长度为177 ± 30 msec。在每种情况下，心房扑动回路都局限于右心房，左心房被被动激活。心房扑动回路依赖于游离壁传导阻滞引起的心肌通道，该通道由全腔静脉连接的外侧缘产生。在任何情况下，心房切开术都不是心房扑动回路的组成部分。本研究确定，在短期犬模型中，仅全腔静脉连接挡板缝线（不改变循环生理学）就可为房扑创建足够的解剖学基础。折返回路解剖边界的划定提高了回路内可修改的靶向区域的可能性，从而可能降低全腔静脉连接后术后房扑的发生率。（J THORAC CARDIOVASC SURG 1996;111：514-26）
Intraatrial reentrant tachycardia, or atrial flutter, is a common postoperative problem after Fontan repair, which involves an atriopulmonary connection. A modification of Fontan repair, total cavopulmonary connection, minimizes the portion of the right atrium exposed to stretch and hypertension; however, atrial flutter continues to occur after this procedure. We postulated that the intraatrial lateral tunnel suture line of total cavopulmonary connection, in the absence of physiologic alterations such as atrial hypertension or stretch, provides the necessary electrophysiologic substrate for atrial flutter. The purpose of this study was to produce a canine model of total cavopulmonary connection (1) to establish that the intraatrial suture line alone is sufficient to permit sustained atrial flutter and (2) to characterize the pathways of resulting reentrant arrhythmias. After induction of general anesthesia, 25 to 30 kg dogs ( n = 17) underwent median sternotomy, cradling of the pericardium, and placement of a pacing electrode on the right atrial appendage. Normothermic cardiopulmonary bypass was initiated. The total cavopulmonary connection suture line was placed through a standard right atriotomy, simulating construction of the lateral tunnel. After closure of the atriotomy, 253 point unipolar atrial endocardial form-fitting electrodes were placed through bilateral ventriculotomies. By means of atrial burst pacing and programmed extrastimulation, induction of atrial flutter was attempted. If atrial flutter could not be induced, isoproterenol was infused and the stimulation protocol was repeated. After induction of atrial flutter, mapping of the activation sequence was performed. Before suture line placement, no dog had inducible atrial flutter. After placement of the suture line, sustained atrial flutter was reproducibly induced in every dog, although isoproterenol was required for this in three (17.6%). The mean flutter cycle length was 177 ± 30 msec. In each case, the atrial flutter circuit was limited to the right atrium, with the left atrium being passively activated. The atrial flutter circuit was dependent on a corridor of myocardium that resulted from conduction block on the free wall, created by the lateral margin of the total cavopulmonary connection. In no case was the atriotomy integral to the atrial flutter circuit. This study establishes that the total cavopulmonary connection baffle suture line alone, without alteration in circulatory physiology, creates a sufficient anatomic substrate for atrial flutter in a short-term canine model. Delineation of the anatomic boundaries of the reentrant circuit raises the possibility of targeting areas within the circuit that could be modified, potentially reducing the incidence of postoperative atrial flutter after total cavopulmonary connection. (J THORAC CARDIOVASC SURG 1996;111:514-26)