Prognostic Value of Time Dependent Voltage Abatement During Remote Magnetic Navigation Guided Ablation in Idiopathic Right Ventricular Outflow Tract Arrhythmias

Abstract

Prognostic value of time dependent voltage abatement during remote magnetic navigation guided ablation in idiopathic right ventricular outflow tract arrhythmias Purpose: 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 (AAD).Results: After 3 months 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 sec (p=0,045). The time intervals from the onset of RF delivery (t0) to significant voltage abatement (>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 ± 16,97μV/s (P=0,024). Conclusion: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.