Roberts-Thomson Kurt C, Stevenson Irene H, Kistler Peter M, Haqqani Haris M, Goldblatt John C, Sanders Prashanthan, Kalman Jonathan M
Department of Cardiology, Royal Melbourne Hospital, and the University of Melbourne, Melbourne, Australia.
J Am Coll Cardiol. 2008 Feb 26;51(8):856-62. doi: 10.1016/j.jacc.2007.11.037.
This study sought to characterize the conduction properties of the posterior left atrium (PLA) in patients with different forms of structural heart disease undergoing cardiac surgery.
The PLA plays an important role in the initiation and maintenance of atrial fibrillation.
This study included 34 patients having elective cardiac surgery. There were 4 groups of patients: normal left ventricular (LV) function (coronary artery bypass grafting [CABG]); severe LV dysfunction (LVF/CABG); severe mitral regurgitation (MR); severe aortic stenosis (AS). Epicardial mapping of the PLA was performed in sinus rhythm and during differential pacing. Activation patterns, regional conduction velocity (CV), conduction heterogeneity, anisotropy, and total plaque activation time (TAT) were assessed.
Left atrial size in patients with LVF/CABG (47 +/- 7 mm) and MR (54 +/- 6 mm) was larger than patients with CABG (39 +/- 7 mm) and AS (42 +/- 6 mm; p < 0.05). During pacing, all patients developed a vertical line of conduction delay running between the pulmonary veins. The extent of this conduction delay was greater in patients with LVF/CABG and MR than patients with AS and CABG (p < 0.05). Conduction heterogeneity, anisotropy, and TAT were greater in patients with LVF/CABG and MR than patients with CABG (p < 0.05). These changes resulted in circuitous wave front propagation.
There is a line of functional conduction delay in a consistent anatomical location in the PLA in patients with structural heart disease. This is most marked in conditions associated with significant chronic atrial enlargement and leads to circuitous wave front propagation, suggesting a potential role in arrhythmogenesis.
本研究旨在对接受心脏手术的不同类型结构性心脏病患者左房后壁（PLA）的传导特性进行表征。
PLA在房颤的起始和维持中起重要作用。
本研究纳入34例行择期心脏手术的患者。患者分为4组：左心室（LV）功能正常（冠状动脉旁路移植术[CABG]）；严重LV功能障碍（LVF/CABG）；严重二尖瓣反流（MR）；严重主动脉瓣狭窄（AS）。在窦性心律和差异性起搏期间对PLA进行心外膜标测。评估激动模式、局部传导速度（CV）、传导异质性、各向异性和总斑块激动时间（TAT）。
LVF/CABG组（47±7mm）和MR组（54±6mm）患者的左房大小大于CABG组（39±7mm）和AS组（42±6mm；p<0.05）。起搏期间，所有患者均在肺静脉之间出现一条垂直的传导延迟线。LVF/CABG组和MR组患者的这种传导延迟程度大于AS组和CABG组患者（p<0.05）。LVF/CABG组和MR组患者的传导异质性、各向异性和TAT大于CABG组患者（p<0.05）。这些变化导致波阵面呈迂回传播。
结构性心脏病患者的PLA在一致的解剖位置存在一条功能性传导延迟线。这在与显著慢性心房扩大相关的情况下最为明显，并导致波阵面呈迂回传播，提示其在心律失常发生中可能起作用。
