Abstract
Identifying arrhythmogenic sites to improve ventricular tachycardia (VT) ablation outcomes remains unresolved. The re-entry vulnerability index (RVI) combines activation and repolarization timings to identify sites critical for re-entrant arrhythmia initiation without inducing VT.
ObjectiveTo provide the first assessment of RVI’s capability to identify VT sites of origin using high-density contact mapping and comparison with other activation-repolarization markers of functional substrate.
Methods18 VT ablation patients (16M, 72% ischemic) were studied. Unipolar electrograms were recorded during ventricular pacing and analysed off-line. Activation time (AT), activation-recovery interval (ARI), repolarization time (RT) were measured. Vulnerability to re-entry was mapped based on RVI and spatial distribution of AT, ARI and RT. The distance from sites identified as vulnerable to re-entry to the VT site of origin was measured, with distances <10 mm and >20 mm indicating accurate and inaccurate localization, respectively.
ResultsThe origin of 18 VTs was identified (n=6 entrainment, n=12 pace-mapping). RVI maps included 1012, 408—2098 (median, 1st—3rd quartiles) points/patient. RVI accurately localized 72.2% VT sites of origin, with median distance equal to 5.1, 3.2—10.1 mm. Inaccurate localization was significantly less frequent for RVI than AT (5.6% vs 33.3%, OR=0.12, P=0.035). Compared to RVI, distance to VT sites of origin was significantly larger for sites showing prolonged RT and ARI, and non-significantly larger for sites showing highest AT and ARI gradients.
ConclusionRVI identifies vulnerable regions closest to VT sites of origin. Activation-repolarization metrics may improve VT substrate delineation and inform novel ablation strategies.
Original language | English |
---|---|
Journal | Heart Rhythm |
Early online date | 18 Nov 2019 |
DOIs | |
Publication status | E-pub ahead of print - 18 Nov 2019 |