The TRAMPOLINE VT Study

Trial of Rapid Activation MaPping Using a nOveL Catheter and Integrated Non-invasivE Imaging in Ventricular Tachycardia

This non-randomised, prospective trial will examine the feasibility and efficacy of VT ablation guided by activation mapping using the Octaray catheter and the CARTO3 electro-anatomical mapping system. Procedures will integrate data from cardiac MRI and voltage mapping to identify sites of interest for focussed activation mapping; the investigators hypothesise that the examination of these data will identify critical target sites for ablation. Intra-procedural diagnostic performance of the Octaray will be assessed as the primary outcome, and will be compared with the standard of care. Secondary, clinical outcomes - primarily the need for ICD therapies at 12 months post ablation - will be compared with propensity-matched controls undergoing substrate-based ablation alone.

Identified retrospectively from registry data: propensity matched-controls undergoing VT ablation guided by substrate-modification alone.

The site of VT origin suggested by activation mapping will be confirmed by either: i) Termination with ablation at this site ii) Entrainment of the tachycardia at this site (concealed fusion with PPI-TCL <30ms and equivalent stimulus-QRS interval to EGM-QRS (30-70% TCL) interval) iii) Pace-mapping (average correlation coefficient >90%)

The VT diastolic interval will be divided into temporal segments: i) First third: VT entrance ii) Middle third: VT isthmus iii) Final third: VT exit Completeness of diastolic pathway recording will be assessed according to the number of segments in which electrical activity is recorded

ICD devices will be interrogated at 3 and 12 months post ablation, or according to clinical need, and the requirement for appropriate anti-tachycardia pacing (ATP) or defibrillation recorded

ICD devices will be interrogated at 3 and 12 months post ablation, or according to clinical need, and the number and duration of recorded VT episodes noted

The Arrhythmia-specific questionnaire in Tachycardia and Arrhythmia (ASTA) will be completed both before and 12 months following ablation to assess for quantitative change in arrhythmia-related symptomatology

Cardiac MRI (CMR) will be performed before and 3 months post ablation. Changes in functional, volumetric and scar-related data will be recorded

Inclusion Criteria: ICD in situ Clinical indication for VT ablation; incessant VT or receiving appropriate ICD therapies for VT despite anti-arrhythmic drugs Ischaemic or non-ischaemic heart disease Exclusion Criteria: Valvular heart disease precluding LV access Cardiotomy within previous 3 months Acute coronary syndrome within 6 weeks Dialysis patients Coagulopathy/Thrombocytopaenia Pregnancy/breastfeeding women CMR contraindicated Prognosis <12 months Unable to provide informed consent