Ventricular arrhythmias ablated successfully in the subvalvular interleaflet triangle between the right and left coronary cusps: Electrophysiological characteristics and catheter ablation

Heart Rhythm. 2021 Dec;18(12):2148-2157. doi: 10.1016/j.hrthm.2021.08.019. Epub 2021 Aug 24.

Abstract

Background: Ventricular arrhythmias (VAs) ablated successfully at the right-left subvalvular interleaflet triangle (R-L ILT) between right and left coronary cusps have not been fully characterized.

Objective: The purpose of this study was to investigate the electrophysiological characteristics of these VAs and their relationships with the left ventricular (LV) summit.

Methods: Twenty-eight VAs ablated successfully at the R-L ILT were studied.

Results: Ninety-six percent of VAs had an early precordial electrocardiographic transition. R-wave amplitude in lead V1 was relatively high (RS morphology, R-wave amplitude 0.35 ± 0.09 mV; R/S ratio 0.35 ± 0.27), whereas the morphology of lead I was R-shaped in 71% and M-shaped in 50% of VAs. Earliest potential was recorded at the R-L ILT in 13 of 28 patients and the left pulmonary sinus cusp (LC) in 6 of 28 patients. Mapping the summit communicating vein (summit-CV) failed because of anatomic or instrumental limitations in these 19 patients. In the other 9 patients, earliest potential was successfully recorded at the summit-CV, while perfect pacemapping was achieved. Poor pace mapping was achieved at the R-L ILT or LC in most patients (27/28). Target site was located at the top of the R-L ILT in all cases. A presystolic potential was present at the target site in 18 of 28 patients. A U-curve via the retrograde method was conventionally used to reach the top of the R-L ILT.

Conclusion: VAs ablated successfully at the R-L ILT have unique electrophysiological characteristics, and R-L ILT may be an endocardial anatomic ablation target for VAs originating from the base of the LV summit.

Keywords: Catheter ablation; Interleaflet triangle; Left pulmonary sinus cusp; Summit communicating vein; Ventricular arrhythmias.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Surface Potential Mapping / methods*
  • Cardiac Electrophysiology
  • Catheter Ablation* / adverse effects
  • Catheter Ablation* / methods
  • Electrocardiography / methods
  • Electrophysiologic Techniques, Cardiac / methods
  • Female
  • Heart Conduction System* / pathology
  • Heart Conduction System* / physiopathology
  • Humans
  • Male
  • Tachycardia, Ventricular* / diagnosis
  • Tachycardia, Ventricular* / physiopathology
  • Tachycardia, Ventricular* / therapy
  • Treatment Outcome