Ablating Left-sided Atrioventricular Accessory Pathways in Young Patients with Persistent Left Superior Vena Cava: Start in the Coronary Sinus

Sep 29, 2026

Persistent left superior vena cava (PLSVC) draining into the coronary sinus (CS) may be hemodynamically insignificant yet create important challenges during electrophysiology study and catheter ablation. Ablation of left-sided accessory pathways is difficult due to potential mitral valve annulus distortion and the possibility that the pathway extends as a discrete epicardial trunk involving CS musculature. Successful ablation is often achieved from within the CS rather than from the mitral annulus after transseptal puncture. Two pediatric cases are presented where CS-based ablation succeeded after failed attempts on the mitral valve.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages5

Reading Time13 min

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Abstract

Introduction

Case presentations

Case 1

Case 2

Discussion

J Innov Cardiac Rhythm Manage. 2025;16(12):6520–6524 DOI: 10. 19102/icrm.2025.16121 CATHETER ABLATION PEDIATRIC EP CASE REPORT Ablating Left-sided Atrioventricular Accessory Pathways in Young Patients with Persistent Left Superior Vena Cava: Start in the Coronary Sinus SOHAM DASGUPTA, md 1 and CHRISTOPHER JOHNSRUDE, md, ms 1 1Division of Pediatric Cardiology, Department of Pediatrics, Norton Children’s Hospital, University of Louisville, Louisville, KY, USA ABSTRACT. While hemodynamically insignificant, a persistent left superior vena cava (PLSVC) draining to the coronary sinus (CS) may have important implications during an electrophysiology study and catheter ablation. Specifically, ablation of left-sided accessory pathways (APs) poses a special challenge secondary to the potential distortion of the mitral valve annulus (MVA) and the possibility of the AP comprising a discrete epicardial trunk involving CS musculature. Ablation of such pathways is more likely accomplished from within the CS rather than on the MVA after a transseptal puncture. We describe two pediatric cases with a PLSVCdraining to a dilated CS in whom successful ablation of left-sided APs was accomplished from within the CS after failed ablation attempts on the MVA. Initial mapping and ablation in the CS after a careful evaluation of the coronary artery proximity may obviate the need for a transseptal puncture with its potential challenges. KEYWORDS. Ablation, coronary sinus, pediatrics, persistent left superior vena cava. ISSN 2156-3977 (print) ISSN 2156-3993 (online) CC BY 4.0 license © 2025 Innovations in Cardiac Rhythm Management Introduction Persistent left superior vena cava (PLSVC) is a congenital anomaly of the thoracic venous system resulting from abnormal embryological regression, which usually drains into the right atrium via a patulous coronary sinus (CS) .1 This anomaly does not impose significant hemodynamic consequences and is often discovered incidentally on cardiovascular imaging or during invasive cardiovascular procedures.1 However, a PLSVC may pose procedural challenges for patients presenting The authors report no conflicts of interest for the published content. No funding information was provided. Manuscript received August 13, 2025. Final version accepted September 5, 2025. Address correspondence to: Soham Dasgupta, MD, Division of Pediatric Cardiology, Department of Pediatrics, Norton Children’s Hospital, University of Louisville, 231 E Chestnut St., Louisville, KY 40202, [USA. Email: dasguptasoham@gmail.com](USA. Email: dasguptasoham@gmail.com). for catheter ablation to treat supraventricular tachycardia (SVT),2 including anatomic distortions affecting electrophysiological (EP) mapping within the triangle of Koch in patients with atrioventricular (AV) nodal re-entry tachycardia (AVNRT),3 atypical anatomy and courses of AV accessory pathways (APs) in those with AV re-entry tachycardia (AVRT),4 and potentially challenging transseptal puncture procedure related to congenital septal anatomy.2 While successful catheter ablation of left-sided APs on the mitral valve annulus (MVA) has been described in adult patients with PLSVC, there are limited reports of catheter ablation within the PLSVC5,6 in children, some of whom had concomitant congenital heart defects (CHDs) . Herein, we describe successful catheter ablation within the PLSVC to treat two young patients with AVRT and CHD, after unsuccessful ablation had been performed on the MVA via a transseptal approach. 6520 The Journal of Innovations in Cardiac Rhythm Management, December 2025 Ablating Left-sided AVAPs in Young Patients with PLSVC This study was approved by the institutional review board at Norton Children’s Hospital. Case presentations Case 1 A 9-year-old girl born with multiple restrictive ventricular septal defects (VSDs) and Wolff–Parkinson– White (WPW) syndrome had been previously treated with flecainide. After her WPW syndrom

FAQs

Why can ablation of left-sided accessory pathways be challenging in patients with PLSVC?

It may distort the mitral valve annulus and the accessory pathway may involve CS musculature as an epicardial trunk, making mitral-annulus targeting difficult.

Where were successful ablations performed in the reported pediatric cases?

Successful ablations were accomplished within the coronary sinus after initial ablation attempts on the mitral valve failed.

What procedural strategy may reduce the need for transseptal puncture?

Initial mapping and ablation in the CS, supported by careful evaluation of coronary artery proximity, may obviate transseptal puncture and its related challenges.

Sep 29, 2026

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