Abstract：
BACKGROUND: 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.
METHODS: We studied consecutive patients with idiopathic VAs originating from the LVS (67 patients) and aortic root (93 patients).
RESULTS: 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).
CONCLUSIONS: Septal-LVS VAs are considered a distinct subgroup of idiopathic VAs originating from the left ventricular outflow tract.
METHODS: We studied consecutive patients with idiopathic VAs originating from the LVS (67 patients) and aortic root (93 patients).
RESULTS: 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).
CONCLUSIONS: Septal-LVS VAs are considered a distinct subgroup of idiopathic VAs originating from the left ventricular outflow tract.
摘要：
背景：左心室峰顶（LVS）是左心室心外膜表面的最高点。位于左冠状动脉之间的LVS的一部分（外侧LVS）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VAs可以在心内膜区域与外侧LVS（间隔LVS）相邻的心外膜区域进行消融。这项研究检查了间隔LVSVA的患病率，心电图和电生理特征。
方法：我们研究了来自LVS（67例）和主动脉根部（93例）的特发性VAs的连续患者。
结果：根据消融结果，在67个LVSVAs中，54个被分类为外侧，13个被分类为间隔LVSVA。与横向LVSVA相比，室间隔-LVSVAs的特征是左束支传导阻滞伴左下轴QRS图的患病率更高，后来的心前过渡，导线III至II中的较低R波振幅比，较低的Q波振幅比在引线aVL到aVR，以及相对于心脏大静脉中的VAs（V-QRS）期间QRS发作的局部心室激动时间。间隔LVSVA的心电图和电生理特征与主动脉根VA相似。然而,在间隔LVSVAs期间,成功消融部位的V-QRS明显晚于主动脉根部VAs(p<.0001)。在间隔-LVSVAs期间，心前区转变明显晚于主动脉根VAs（p<0.05）。
结论：Septal-LVSVAs被认为是起源于左心室流出道的特发性VAs的独特亚组。
方法：我们研究了来自LVS（67例）和主动脉根部（93例）的特发性VAs的连续患者。
结果：根据消融结果，在67个LVSVAs中，54个被分类为外侧，13个被分类为间隔LVSVA。与横向LVSVA相比，室间隔-LVSVAs的特征是左束支传导阻滞伴左下轴QRS图的患病率更高，后来的心前过渡，导线III至II中的较低R波振幅比，较低的Q波振幅比在引线aVL到aVR，以及相对于心脏大静脉中的VAs（V-QRS）期间QRS发作的局部心室激动时间。间隔LVSVA的心电图和电生理特征与主动脉根VA相似。然而,在间隔LVSVAs期间,成功消融部位的V-QRS明显晚于主动脉根部VAs(p<.0001)。在间隔-LVSVAs期间，心前区转变明显晚于主动脉根VAs（p<0.05）。
结论：Septal-LVSVAs被认为是起源于左心室流出道的特发性VAs的独特亚组。
