Relationship between electroanatomical voltage mapping characteristics and breakout site of ventricular activation in idiopathic ventricular tachyarrhythmia originating from the right ventricular outflow tract septum

Abstract

The border area, including the LVA, tends to be the breakout site and/or origin of ventricular arrhythmias in idiopathic ventricular tachyarrhythmia originating from the RVOT septum.

Disappearance of Idiopathic Outflow Tract Premature Ventricular Contractions After Catheter Ablation of Overt Accessory Pathways

“…Therefore, the occurrence of these PPs and their association with His‐bundle activation time suggests that islets of residual cells (located within the fibrous trigone) that once originated from the conduction system and failed to regress during maturation might be actively involved in the genesis of VAs originating from this region. Similar findings have been described in several reports …”

Right ventricular outflow tract low‐voltage areas identify the site of origin of idiopathic ventricular arrhythmias: A high‐density mapping study

“…The mean number of points sampled in this study was 158 ± 34. In a similar study where 148 ± 27 points were sampled per patient, the SOO was identified at the border area (mean amplitude of 1.9 ± 0.3 mV) in 19 of the 28 patients …”

“…Second, a relatively small number of patients with low‐arrhythmia burden has been included for analysis. Third, abnormal local bipolar electrograms during sinus rhythm were defined as those displaying an amplitude of less than 1 mV, which is different from previous studies . However, we do believe that these thresholds are dependent on the electrode size and spacing.…”

“…However, c‐MRI may lack sensitivity in identifying substrate abnormalities in the right ventricle . Data regarding electronatomical abnormalities in successful ablation sites of idiopathic RVOT VAs are limited and based on low resolution mapping . We hypothesized that high‐density endocardial bipolar voltage mapping during sinus rhythm may detect minimal electrical abnormalities within the RVOT that possibly represent the arrhythmogenic substrate and therefore targets for successful catheter ablation.…”

Ablation of the vanishing PVC, facilitated by quantitative morphology‐matching software

“…Pace mapping template matches over 92% performed using the Biosense Webster PaSo software was helpful in defining a successful ablation site in 13/17 VA ablated using pace mapping only. Other confirmatory findings at these sites included observing presystolic potentials, and induction of VT that had a similar QRS morphology to the spontaneous arrhythmia during RF energy delivery at these sites …”