TY - JOUR T1 - Novel repolarisation metric predicts arrhythmia origin and clinical events in ARVC and Brugada Syndrome JF - bioRxiv DO - 10.1101/123422 SP - 123422 AU - CA Martin AU - M Orini AU - N Srinivasan AU - J Bhar-Amato AU - S Honarbakhsh AU - A Chow AU - MD Lowe AU - RD Simon AU - PM Elliott AU - P Taggart AU - PD Lambiase Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/04/03/123422.abstract N2 - Background Initiation of re-entrant ventricular tachycardia (VT) involves complex interactions between activation (AT) and repolarization times (RT). The re-entry vulnerability index (RVI) is a recently proposed activation-repolarization metric designed to quantify tissue susceptibility to re-entry.Objectives The study aimed to test the feasibility of an RVI-based algorithm to predict the exit site of VT and occurrence of clinical events.Methods Patients with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (n=11), Brugada Syndrome (BrS) (n=13) and focal RV outflow tract VT (n=9) underwent programmed stimulation with unipolar electrograms recorded from a non-contact array. The distance between region of lowest RVI and site of VT breakout (Dmin), and global minimum RVI (RVIG) were computed to assess prediction of site of VT breakout and occurrence of clinical events, respectively.Results Lowest values of RVI, representing sites of highest susceptibility to re-entry, co-localised with site of VT breakout in ARVC/BrS but not in focal VT and Dmin values were lower in ARVC/BrS. ARVC/BrS patients with inducible VT had lower RVIG than those who were non-inducible or those with focal VT. Patients were followed up for 112 ± 19 months; those with clinical VT events had lower RVIg than those without VT or those with focal VT.Conclusions The proposed methodology based on RVI localises the origin of re-entrant but not focal ventricular arrhythmias and predicts clinical events. This index could be applied to target ablation for arrhythmias which are difficult to induce or are haemodynamically unstable and also risk stratify patients for ICD prophylaxis.ATActivation timeRTRepolarization timeRVIRe-entry vulnerability indexARVCArrhythmogenic Right Ventricular CardiomyopathyBrSBrugada SyndromeVTVentricular tachycardiaRVOTRight ventricular outflow tractEPSElectrophysiological studyVERPVentricular effective refractory periodATActivation timeRTRepolarization timeRVIRe-entry vulnerability indexARVCArrhythmogenic Right Ventricular CardiomyopathyBrSBrugada SyndromeVTVentricular tachycardiaRVOTRight ventricular outflow tractEPSElectrophysiological studyVERPVentricular effective refractory period ER -