Prognostic value of time dependent voltage abatement during remote magnetic navigation guided ablation in idiopathic right ventricular outflow tract arrhythmias

Backgrounds: We set out to evaluate if time related voltage abatement (dV/dt) of ventricular electrograms (EGM) during catheter ablation of idiopathic right ventricular outflow tract (RVOT) arrhythmias using the Stereotaxis Niobe II system is an efficient marker of long-term procedural success. Methods: Twenty-six consecutive patients with acute success of RVOT ablation for premature ventricular contractions (PVCs) and/or ventricular tachycardia (VT) suggestive of RVOT origin were included. Late success was defined as freedom of ventricular ectopies originating from the RVOT after 3 months of follow-up without antiarrhythmic drugs (MD). Results: After 3-month follow-up 20 of 26 patients (77%) remained free of symptoms and arrhythmias (group 1) and recurrences occurred in 6 patients (23%) (group 2). 'Warming up' during RF applications occurred respectively in 85% and 83.33% of patients (p = 0.46), after a mean period (dt 2) of 4.72 +/- 9.42 vs 10.75 +/- 11.34 s (p = 0.045). The time intervals from the onset of RF delivery (t0) to significant voltage abate merit (>90%) or reversal of EGM polarity (t1) between the two groups were: 9.11 +/- 5.11 vs 32.16 +/- 10.33 (p = 0.00006). dV/dt1 was 95.44 +/- 87.6 vs 23.5 +/- 16.97 pV/s (p = 0.024). Conclusions: Time related voltage abatement of ventricular EGM together with time interval from onset of RF ablation to significant voltage abatement (>90%) or reversal of EGM polarity and time interval from RF delivery to onset 'warming up' are possible predictors of long-term success after RF ablation of idiopathic RVOT arrhythmias.