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Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction
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Catheter Ablation of Triggers and Arrhythmogenic Epicardial Substrates in Patients with QT Prolongation

Yoga Yuniadi1, Dicky A Hanafy1, Sunu B Raharjo1

  • 1Department of Cardiology and Vascular Medicine, Faculty of Medicine, Universitas Indonesia, and National Cardiovascular Center Harapan Kita, Jakarta, Indonesia.

Archives of Medical Research
|July 2, 2025
PubMed
Abstract

Insights

Radiofrequency ablation of ventricular premature contraction (VPC) triggers and localized abnormal ventricular activities (LAVAs) in Long QT syndrome (LQTS) patients showed modest success in preventing recurrence. Epicardial mapping identified substrate areas, and ablation shortened the corrected QT interval (QTc).

Area of Science:

  • Cardiology
  • Electrophysiology
  • Genetics

Background:

  • Long QT syndrome (LQTS) ablation is typically reserved for high-risk or refractory cases.
  • Focus has been on eliminating triggers like ventricular premature contractions (VPCs).
  • The underlying substrate and role of radiofrequency ablation in LQTS require further investigation.

Purpose of the Study:

  • To characterize the substrate and triggers of ventricular arrhythmias in LQTS patients.
  • To evaluate the efficacy of radiofrequency ablation for localized abnormal ventricular activities (LAVAs) and VPCs in LQTS.
  • To assess the impact of ablation on corrected QT interval (QTc) and arrhythmia recurrence.

Main Methods:

  • Symptomatic LQTS patients underwent 3-D endocardial and epicardial mapping.
  • Genetic testing was performed to identify causative mutations.
  • Epicardial voltage mapping identified scar and low-voltage areas.
  • Radiofrequency ablation targeted identified LAVAs and VPC triggers.

Main Results:

  • Eight female LQTS patients (36 ± 10.2 years) were studied.
  • Genetic mutations included KCNH2 (P1093A, K28E) and SCN5A (H558R).
  • Thirteen VPC morphologies were identified, originating from various ventricular sites.
  • Epicardial mapping revealed significant scar and low-voltage areas in all patients.
  • Ablation of LAVAs successfully shortened the QTc interval (594.9 ± 85.98 ms to 490 ± 67.49 ms, p = 0.001).
  • Two patients experienced recurrence of ventricular tachycardia (VT) or ventricular fibrillation (VF) during follow-up (mean 288 ± 147.4 days).

Conclusions:

  • Regional and limited epicardial LAVAs can be identified in LQTS patients.
  • Radiofrequency ablation of VPC triggers and epicardial LAVAs offers a modest benefit in preventing VT/VF recurrence.
  • Identifying and ablating epicardial substrates may play a role in managing LQTS-associated arrhythmias.
Keywords:
EndocardialEpicardialLAVALong QT syndromeSubstrate ablation

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