Pulsed-Field Ablation Circular Catheter Use in Left Superior Vena Cava–Associated Atrial Arrhythmias

Abstract

Background

This case presented the first domestic instance of ablation for persistent left superior vena cava (PLSVC)-associated atrial arrhythmia, utilizing the “Varipulse” pulsed-field ablation system.

Case Summary

The computed tomography angiography examination revealed the presence of a PLSVC. During the procedure, left atrial modeling was performed using the CARTO^3D electroanatomical mapping system, and models of the pulmonary veins and PLSVC were manually constructed in conjunction with intracardiac echocardiography. A combined ablation strategy was employed intraoperatively, and after pulsed-field ablation of the earliest activation site in the middle segment of the PLSVC, the patient's rhythm converted to sinus.

Discussion

The “Varipulse” pulsed-field ablation system enables circumferential ablation of atrial fibrillation trigger foci in the PLSVC, achieving rapid, uniform isolation and significantly improving ablation efficiency.

Take-Home Message

The “Varipulse” pulsed-field ablation system offers a novel technical approach for the precise and safe treatment of atrial arrhythmias associated with PLSVC.

Visual Summary

The persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly and frequently serves as a critical substrate for the initiation and maintenance of atrial arrhythmias.¹ Due to the characteristics of traditional ablation energy sources, radiofrequency or cryoablation has significant limitations in managing PLSVC-associated arrhythmias.^2,3 Pulsed-field ablation (PFA) technology achieves tissue ablation by altering cell membrane permeability through high-voltage electrical pulses.⁴ Characterized by excellent tissue selectivity and high ablation efficiency, PFA offers a novel technical approach for the precise and safe treatment of PLSVC-associated atrial arrhythmias.⁵

Take-Home Messages

• •The persistent left superior vena cava frequently serves as a critical substrate for the initiation and maintenance of atrial arrhythmias.
• •The “Varipulse” pulsed-field ablation system offers a novel technical approach for the precise and safe treatment of atrial arrhythmias associated with persistent left superior vena cava.

History of Presentation

The patient is a 71-year-old female who experienced paroxysmal palpitations and chest tightness 20 years ago. Over the past 2 months, her palpitations have intensified, with episodes occurring more frequently. An electrocardiogram revealed atrial fibrillation, and despite treatment with antiarrhythmic medications (propafenone, amiodarone), there was no significant improvement. Clinically, she was diagnosed with drug-refractory, symptomatic paroxysmal atrial fibrillation, leading to the decision to perform catheter ablation. Preoperative computed tomography angiography showed that the patient had a PLSVC, which connected to the left atrium via the coronary sinus (Figures 1A and 1B). In addition, thrombi and anatomical abnormalities of the pulmonary veins were ruled out (Figure 1C).

Figure 1.

Clinical Presentation and Anatomical Landmarks

The preoperative CTA identified a PLSVC communicating with the left atrium via the coronary sinus (CS) (A and B); the pulmonary veins exhibited no anatomical abnormalities (C). AO = aorta; AS = aortic stenosis; CS = coronary sinus; CTA = computed tomography angiography; LA = left atria; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; PLSVC = persistent left superior vena cava; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein.

Management

Intraoperatively, the CARTO 3 3-dimensional electroanatomical mapping system was utilized to model the left atrium, and models of the pulmonary veins and PLSVC were manually constructed in conjunction with intracardiac echocardiography (ICE) (Figures 2A and 2B, Video 1). Given the patient's age over 70, her comorbidities of hypertension and diabetes, and the lack of efficacy from the 2 oral antiarrhythmic drugs she was taking, the standard pulmonary vein isolation protocol was performed on the bilateral pulmonary veins (Figure 2C), followed by left atrial roof ablation, posterior wall “BOX” ablation, and mitral isthmus ablation, using the VARIPULSE variable-loop circular catheter (Biosense Webster, Inc) (Figure 2D). Following the ablation, the patient's rhythm converted to atrial tachycardia (Figure 2E).

Figure 2.

Anatomical Mapping and Pulsed-Field Ablation Applications to Left Atrium

The pulmonary vein and PLSVC models were manually constructed using ICE (A and B); bilateral PVI was performed using a standard protocol (C); left atrial roof ablation, posterior wall “BOX” ablation, and mitral isthmus ablation were also conducted (D); post ablation, the patient's rhythm converted to atrial tachycardia (E). ICE = intracardiac echocardiography; PLSVC = persistent left superior vena cava; PVI = pulmonary vein isolation.

Considering that the PLSVC frequently acts as a substrate for the initiation and perpetuation of atrial arrhythmias, we conducted activation mapping of the PLSVC through the venous left common carotid catheter during atrial tachycardia. The mapping results indicated the earliest activation site in the mid-section of the PLSVC (Figure 3A, Video 2). Subsequently, PFA was administered at this location (Figure 3B), which terminated the tachycardia after 4 applications and reinstated sinus rhythm (Figure 3C, Video 3). Postprocedural verification confirmed the successful isolation of the bilateral pulmonary veins and posterior wall, as well as the mitral isthmus block (Figure 3D).

Figure 3.

Pulsed-Field Ablation Applications to Isolate PLSVC

The activation mapping of the PLSVC using the VLCC indicates that the initial activation occurs in the mid-portion (A). PFA at this site successfully terminates tachycardia and restores sinus rhythm (B and C). Postprocedural verification confirms isolation of the bilateral pulmonary veins and posterior wall, as well as blockage of the mitral isthmus (D). PFA = pulsed-field ablation; PLSVC = persistent left superior vena cava; VLCC = variable-loop circular catheter.

Discussion

As the most common thoracic venous anomaly, PLSVC shares a homologous embryonic origin with the pulmonary veins and the vein of Marshall—all derived from the common cardinal vein.^1,6,7 Consequently, the venous wall contains numerous muscular sleeves. These muscular sleeves form multiple electrophysiological connections with the left atrium through the coronary sinus in a “funnel-shaped or spiral pattern,” an anatomical feature that serves as a critical substrate for its involvement in the initiation and maintenance of atrial arrhythmias.^8,9 Traditional treatment approaches for atrial arrhythmias involving PLSVC, including cryoablation and radiofrequency ablation, have significant limitations. These limitations include uneven energy transmission via radiofrequency and cryoablation, as well as potential damage to phrenic nerve, stroke, and pericardial effusion.³ PFA technology achieves tissue ablation by altering cell membrane permeability through high-voltage electrical pulses, offering advantages such as high tissue selectivity and high ablation efficiency for PLSVC-associated atrial arrhythmias.^4,5 The “variable-loop circular catheter” design of The “Varipulse” PFA system can cover the atrial fibrillation trigger foci (muscular sleeves) in the PLSVC through circumferential ablation, achieving rapid and uniform isolation of the foci and significantly improving ablation efficiency.¹⁰

This case study successfully treated PLSVC-associated atrial arrhythmias via the “Varipulse” PFA system with a combined ablation strategy, including pulmonary vein isolation, left atrial roof line ablation, posterior wall “BOX” ablation, mitral isthmus linear ablation, and PFA of the earliest activation site in the middle segment of the PLSVC. This represents the first application of the “Varipulse” PFA system in a patient with PLSVC. The combination of the “Varipulse” PFA system and the CARTO 3 three-dimensional electroanatomical mapping system provides a safer, more reliable, and effective ablation strategy for ablations involving special anatomical structures. This clinical practice offers a new technique for the precise and safe treatment of PLSVC-associated atrial arrhythmias.

Conclusions

The “Varipulse” PFA system provides a new technical approach for the precise and safe treatment of PLSVC-associated atrial arrhythmias.

Ethical Approval and Consent to Participate

The ethics committee approval from the authors' institution and patients' informed consent have been obtained for this study.

Data Availability Statement

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Visual Summary.

Steps for Ablating the Persistent Left Superior Vena Cava–Associated Atrial Arrhythmia Using the “Varipulse” Pulsed-Field Ablation System

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

Manual Construction of the PLSVC Model Using the CARTO 3 Combined with ICE

Video 2

Electroanatomical Mapping Identifies the Mid-Section of the PLSVC as the Earliest Activation Site of Tachycardia

Video 3

Successful Termination of Tachycardia Following Pulsed Field Ablation at the Mid-Section of the PLSVC