Santangeli Pasquale, Hutchinson Mathew D, Supple Gregory E, Callans David J, Marchlinski Francis E, Garcia Fermin C
From the Department of Medicine, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia.
Circ Arrhythm Electrophysiol. 2016 Jul;9(7). doi: 10.1161/CIRCEP.116.004048.
The posterior-superior process of the left ventricle (PSP-LV) is the most inferior and posterior aspect of the basal LV that extends posteriorly to the plane of the tricuspid valve. The PSP-LV is anatomically adjacent to the inferior and medial aspect of the right atrium (RA). We report a series of patients with ventricular arrhythmias (VAs) arising from the PSP-LV and describe a mapping and ablation approach from the RA guided by intracardiac echocardiography.
Mapping and ablation of the PSP-LV with an RA approach under intracardiac echocardiography guidance were performed in 5 patients with VAs (aged 44±14 years, 2 males) who had failed ablation attempts from multiple endocardial and epicardial (1 patient) sites. Mapping of the PSP-LV from the adjacent inferomedial RA was performed at sites anatomically opposite to the earliest endocardial site of activation under direct intracardiac echocardiography visualization. From the RA side of the PSP-LV, a small atrial signal and a larger ventricular signal were recorded in each case, with an activation time of 32±7 ms pre-QRS (versus 16±5 ms pre-QRS in the LV endocardium; P=0.068). We were able to capture the LV from these sites. Cryoablation was performed in 2 patients, and radiofrequency was used in the remaining 3 cases. In all patients, ablation from the RA eliminated the arrhythmia. All patients remained free of recurrent VAs after a mean follow-up of 12 (7-16) months. There were no immediate or long-term complications.
The PSP-LV can be a site of origin of VAs, which can be successfully eliminated from the adjacent RA under direct intracardiac echocardiographic visualization.
左心室后上嵴（PSP-LV）是左心室基底部最靠下和靠后的部分，向后延伸至三尖瓣平面。PSP-LV在解剖学上与右心房（RA）的下内侧相邻。我们报告了一系列起源于PSP-LV的室性心律失常（VA）患者，并描述了一种在心腔内超声心动图引导下从RA进行标测和消融的方法。
对5例VA患者（年龄44±14岁，男性2例）进行了心腔内超声心动图引导下经RA途径对PSP-LV的标测和消融，这些患者曾在多个心内膜和心外膜（1例）部位进行消融尝试但均失败。在直接心腔内超声心动图可视化下，在与最早的心内膜激动部位解剖学相对的部位，从相邻的RA对PSP-LV进行标测。在PSP-LV的RA侧，每例均记录到一个小的心房信号和一个较大的心室信号，QRS波前的激动时间为32±7毫秒（而左心室心内膜为16±5毫秒；P=0.068）。我们能够从这些部位激动左心室。2例患者进行了冷冻消融，其余3例使用了射频消融。在所有患者中，经RA消融消除了心律失常。平均随访12（7-16）个月后，所有患者均未再发VA。无即刻或长期并发症。
PSP-LV可能是VA的起源部位，在心腔内超声心动图直接可视化下，可从相邻的RA成功消除VA。
