Pranav Bhagirath

194 Chapter 10 Table 1. Characteristics of subjects undergoing inverse potential mapping. Volunteers Patients n 3 8 Age (years) 28 ± 3 46 ± 13 BMI 22.1 ± 1.4 25.2 ± 6.7 Female (%) 1 (33%) 7 (88%) LVEF (%) 55 ± 2 50 ± 3 RVOT PVC’s - 6 (75%) Duration of PVC’s (months) - 18 ± 12 PVC burden pre procedure - 14,121 (IQR: 10432-22373) PVC burden post procedure - 17 (IQR: 1-24) Age, BMI, LVEF and PVC duration are expressed in mean ± standard deviation. PVC burden pre- and post-procedure is expressed using median and IQR. IQR indicates interquartile range. PVC burden is expressed in ectopic beats/24 hours. Ablation procedure The pre-procedural median PVC burden was 14,121 (interquartile range: 10432-22373) ectopic beats/24 hours. Average procedural time, including mapping and ablation, was 129±53 minutes. An average of 4468 points were acquired to construct the EAM. No peri-procedural displacements of the EAM were observed. After catheter ablation, the PVC burden was reduced to a median of 17 (interquartile range:1-24) ectopic beats/24 hours, a reduction of more than 99%. IPM in sinus rhythm During sinus rhythm, the first point of activation on the potential map of healthy volunteers was anatomically located near the transition of the superior vena cave (crista terminalis) (white arrow) into the right atrium ( figure 1a ). Ventricular breakthrough initiated at the right ventricular free wall ( figure 1b ) at the site where the moderator band was attached to the ventricular myocardium. Comparison between IPM focus and actual ablation site No pacing maneuvers were required for PVC induction. Five patients required isoproterenol to induce PVC. Based on invasive mapping, six patients had the ablation site in the right ventricular outflow tract (RVOT) and two in the left ventricular outflow tract (LVOT) ( table 2 ). One of the patients had a right bundle branch block (RBBB) which was reconstructed correctly by IPM (movie 1).