Right Atrial Approach for Ablation of Ventricular Arrhythmias Arising From the Left Posterior–Superior Process of the Left Ventricle

Abstract

T he posterior-superior process of the left ventricle (PSP-LV) is the portion of the basal LV wall in its most inferior and posterior aspect extending above-or basal-to the plane of the tricuspid valve. [1][2][3] As such, the PSP-LV is anatomically adjacent to the inferomedial aspect of the right atrium (RA). To our knowledge, there has been no report of ventricular arrhythmias (VAs) originating from the PSP-LV. We describe 5 cases of VAs arising from the PSP-LV, which were mapped and successfully ablated from the adjacent inferomedial RA overlying the PSP-LV under intracardiac echocardiography (ICE) guidance. Methods Study PopulationThe study subjects were 5 patients (3 males and 2 females) aged 30 to 60 years with symptomatic recurrent VAs, in whom the successful ablation site was at the PSP-LV ablated from the RA. The clinical and electrophysiological characteristics of the patients are shown in Table. A trial of at least 1 antiarrhythmic drug had failed in all patients. In 2 patients, the index procedure represented the initial ablation attempt. The other 3 patients presented to ablation after ≥1 (range 1-2) prior ablation attempts. All patients had frequent premature ventricular contractions with a preablation burden range 10% to 30% and with evidence of decreased LV function in 3 cases (range of LV ejection fraction 30%-45%). A baseline contrast-enhanced magnetic resonance imaging was performed in 4/5 cases and showed a small area of late gadolinium enhancement only in 1 case (patient no 1). No patients had evidence of significant coronary artery disease at preprocedural stress test and cardiac catheterization. All patients gave written, informed consent before the procedure. Electrophysiological Study and Catheter AblationAntiarrhythmic drugs were discontinued at least 5 half-lives before the procedure; no patient was taking amiodarone. Procedures were performed under conscious sedation. Catheters were positioned in the heart using fluoroscopic guidance. A 6-Fr quadripolar catheter with 5-mm interelectrode distance (Bard Inc, Delran, NJ) was placed at the RV apex. A deflectable 8-Fr mapping/ablation catheter with a 3.5-mm irrigated tip and a 2-mm ring electrode separated by 1 mm (Thermocool, Biosense Webster, Diamond Bar, CA) was advanced to the RA and RV (transvenous approach), LV (retrograde aortic approach), and coronary venous system for mapping. A 64-element phased-array ICE catheter (AcuNav, Acuson, Mountain View, © 2016 American Heart Association, Inc. Original Article Circ Arrhythm ElectrophysiolBackground-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. Methods and Results-Mapping and ab...

Electrophysiological Characteristics and Radiofrequency Catheter Ablation Treatment of Idiopathic Ventricular Arrhythmias Successfully Ablated From the Ostium of the Coronary Sinus

“…Santangeli et al reported that VAs arising from the left posterior-superior process of the LV can be successfully eliminated from the adjacent right atrium. 24 Although these VAs seemed to be similar to those in our report, we did not have any electrophysiological mapping data from the right atrium. Finally, understanding the relationship between the anatomy of the CS and the arrhythmogenic origin was important to mapping.…”

Right atrial position of a return electrode for bipolar ablation of the left posterosuperior process ventricular tachycardia

“…Despite technological progress in unipolar approach (irrigation catheters and contact force measurements), standard energy sources in some situations may be insufficient for creating effective transmural lesion. The complex anatomy of LV base may play a significant role in effective lesion formation . These anatomical conditions include the presence of very thick myocardium and anatomical surroundings such as myocardial bands, intraventricular septum, coronary vessels, valves, and adjacent RA sites .…”

“…The complex anatomy of LV base may play a significant role in effective lesion formation. 1 These anatomical conditions include the presence of very thick myocardium and anatomical surroundings such as myocardial bands, intraventricular septum, coronary vessels, valves, and adjacent RA sites. 2 The use of an irrigated-tip electrode in a unipolar setting may improve success rate; however, higher energy values may increase risk of complications.…”

Successful ablation of premature ventricular contractions originating from the inferoseptal process of the left ventricle using a coronary sinus approach

“…The ISP of the LV, also referred to as the posterior-superior process of the LV, has been described as an inferoposterior region of the septal area of the LV that connects the muscular portion of the interventricular septum to the posterior portion of the LV free wall. 1 , 2 , 3 Ventricular arrhythmias arising from the ISP of the LV have been previously reported and were mapped and successfully ablated from the adjacent inferomedial right atrium (RA) overlying the ISP. 3 The ISP is an ill-defined area, and the coronary sinus (CS) is superiorly adjacent to this area.…”

“…1 , 2 , 3 Ventricular arrhythmias arising from the ISP of the LV have been previously reported and were mapped and successfully ablated from the adjacent inferomedial right atrium (RA) overlying the ISP. 3 The ISP is an ill-defined area, and the coronary sinus (CS) is superiorly adjacent to this area. 2 Herein, we describe 2 cases in whom the ISP arrhythmogenic focus could be targeted effectively only from within the CS.…”