Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, USA.
Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
J Cardiovasc Electrophysiol. 2024 Jun;35(6):1174-1184. doi: 10.1111/jce.16270. Epub 2024 Apr 8.
The left ventricular summit (LVS) is the highest point on the epicardial surface of the left ventricle. A part of the LVS that is located between the left coronary arteries (lateral-LVS) is one of the major sites of idiopathic ventricular arrhythmia (VA) origins. Some idiopathic epicardial VAs can be ablated at endocardial sites adjacent to the epicardial area septal to the lateral-LVS (septal-LVS). This study examined the prevalence and electrocardiographic and electrophysiological characteristics of septal-LVS VAs.
We studied consecutive patients with idiopathic VAs originating from the LVS (67 patients) and aortic root (93 patients).
Based on the ablation results, among 67 LVS VAs, 54 were classified as lateral and 13 as septal-LVS VAs. As compared with the lateral-LVS VAs, the septal-LVS VAs were characterized by a greater prevalence of left bundle branch block with left inferior-axis QRS pattern, later precordial transition, lower R-wave amplitude ratio in leads III to II, lower Q-wave amplitude ratio in leads aVL to aVR, and later local ventricular activation time relative to the QRS onset during VAs (V-QRS) in the great cardiac vein. The electrocardiographic and electrophysiological characteristics of the septal-LVS VAs were similar to those of the aortic root VAs. However, the V-QRS at the successful ablation site was significantly later during the septal-LVS VAs than aortic root VAs (p < .0001). The precordial transition was significantly later during the septal-LVS VAs than aortic root VAs (p < .05).
Septal-LVS VAs are considered a distinct subgroup of idiopathic VAs originating from the left ventricular outflow tract.
左心室顶点（LVS）是左心室心外膜表面的最高点。位于左冠状动脉（外侧-LVS）之间的 LVS 部分是特发性室性心律失常（VA）起源的主要部位之一。一些特发性心外膜 VA 可以在心内膜部位消融，该部位毗邻外侧-LVS 心外膜区域的间隔（间隔-LVS）。本研究检查了间隔-LVS VA 的发生率以及心电图和电生理特征。
我们连续研究了起源于 LVS（67 例）和主动脉根部（93 例）的特发性 VA 患者。
根据消融结果，在 67 例 LVS VA 中，54 例为外侧 LVS VA，13 例为间隔-LVS VA。与外侧-LVS VA 相比，间隔-LVS VA 的特征为 QRS 波呈左束支传导阻滞伴左下轴，胸前导联过渡较早，III 导联至 II 导联 R 波振幅比值较低，aVL 导联至 aVR 导联 Q 波振幅比值较低，VA 时心大静脉局部心室激活时间（V-QRS）较 QRS 起始时间较晚。间隔-LVS VA 的心电图和电生理特征与主动脉根部 VA 相似。然而，间隔-LVS VA 时成功消融部位的 V-QRS 明显晚于主动脉根部 VA（p<0.0001）。间隔-LVS VA 时胸前导联过渡明显晚于主动脉根部 VA（p<0.05）。
间隔-LVS VA 被认为是起源于左心室流出道的特发性 VA 的一个独特亚组。
