%0 Journal Article
%T Prevalence and electrocardiographic and electrophysiological characteristics of idiopathic ventricular arrhythmias originating from the septal left ventricular summit.
%A Yamada T
%A Litovsky S
%A Neal Kay G
%J J Cardiovasc Electrophysiol
%V 35
%N 6
%D 2024 Jun
%M 38867544
%F 2.942
%R 10.1111/jce.16270
%X 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.