New diagnostic criteria for identifying left-sided ventricular ectopy using non-contact mapping and virtual unipolar electrogram analysis

Nicola Trevisi, John Silberbauer, Andrea Radinovic, Roberto Bavila, Simone Sala, Pasquale Vergara, Paolo Della Bella

Research output: Contribution to journalArticlepeer-review


Aims To assess the efficacy of non-contact mapping for outflow tract premature ventricular contraction (PVC) and ventricular tachycardia (VT) ablation in patients without structural heart disease and a precordial transition at V3 or later and to determine the diagnostic accuracy of new virtual unipolar electrogram criteria for distinguishing left from right-sided foci using a multi-electrode array positioned within the right ventricular outflow tract. Methods and results Virtual unipolar electrograms at early activation (EA) and break out (BO) sites in 100 patients (36 left-sided foci) who underwent acutely successful outflow tract ablation were analysed and voltage and timing-based criteria measured. The best performing parameters were then re-assessed in 41 patients (14 left-sided) prospectively. Of the candidate criteria for determining a left from right-sided focus, the voltage at 20 ms after EA (EA-V20) and the time from BO to QRS onset (BO-QRS) were the best discriminators with area under the curve (AUC) values based on receiver operator characteristics (ROCs) of 0.947 (0.905-0.989), P <0.001, and 0.951 (0.907-0.995), P <0.001, respectively. These two parameters were subsequently assessed prospectively in a further 41 patients (14 left-sided) using the pre-specified cut-off values of -2 mV for EA-V20 and 10 ms for BO-QRS which demonstrated excellent diagnostic accuracy and sufficient inter-beat and inter-observer reproducibility. Conclusions This large single-centre experience demonstrates that a strategy for outflow tract PVC/VT ablation using non-contact mapping allows for excellent success rates. Furthermore, detailed analysis of virtual unipolar electrograms allows accurate and reproducible determination of left from right-sided foci that may be used to guide mapping and ablation.

Original languageEnglish
Pages (from-to)108-116
Number of pages9
Issue number1
Publication statusPublished - Nov 25 2014


  • Catheter ablation
  • Non-contact mapping
  • Premature ventricular beats
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)
  • Medicine(all)


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