None listed
Conditions
Brief summary
Ventricular tachycardia (VT) is a life-threatening electrical disorder in patients with heart disease. Current methods treat VT by widespread ablation of damaged regions in the heart. We aim to test a strategy of focused ablation limited only to those areas that have electrical properties prone to facilitate VT. This will reduce procedural time and improve safety.
Interventions
Exposure: Patients will be eligible if they had had a myocardial infarction, had undergone placement of an implantable cardioverter defibrillator (ICD), and had >1 episode of sustained VT or ICD therapy during treatment with anti-arrhythmic drugs within the previous 6 months.
Intervention: The intervention will be limited VT ablation, in comparison to conventional VT ablation. Limited ablation involves mapping cardiac conduction in sinus rhythm and performing minimal ablation to 1-5 ventricul
Exposure: Patients will be eligible if they had had a myocardial infarction, had undergone placement of an implantable cardioverter defibrillator (ICD), and had >1 episode of sustained VT or ICD therapy during treatment with anti-arrhythmic drugs within the previous 6 months. Intervention: The intervention will be limited VT ablation, in comparison to conventional VT ablation. Limited ablation involves mapping cardiac conduction in sinus rhythm and performing minimal ablation to 1-5 ventricular regions that are designated as critical for VT maintenance by a computer algorithm. The computer-based algorithm is an experimental software developed for the purpose of study. It is based on previous pre-clinical and clinical work and determines a tissue's propensity to be part of VT circuits based on its electrical information in time- and voltage-domain in sinus rhythm. The overall electrogram information is displayed in 3 color-coded maps: mean activation, dispersion in activation and Shannon entropy, and a VT supporting region is identified where sites with latest mean activation, high dispersion and least entropy are clustered together in a small region. Post-ablation, ablation success will be tested by checking VT inducibility using programmed pacing of right or left ventricle with multiple rapid premature stimuli. If VT remains inducible after limited ablation, conventional ablation will be performed. Ablation will be performed by experienced cardiac electrophysiologists at The Townsville hospital. Ablation involves focal application of radiofrequency energy (up to 50Watts as per operator preference) using commercial irrigated steerable catheters enabled with specialized sensors that detect location, force and tip temperature. Typically, limited VT ablation procedure is expected to be of 3-5hours duration, and is comparable to a standard approach VT ablation. Procedure related complications will be recorded from the operation notes and nursing records if necessary.
Sponsors
Townsville Hospital and Health Service
Study design
Allocation
Non-randomised trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
19 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Patients will be over 18 years of age (not inclusive) and meet standard requirements for catheter ablation of VT. Patients will be eligible if they had had a myocardial infarction, had undergone placement of an implantable cardioverter defibrillator (ICD), and had >1 episode of sustained VT or ICD therapy during treatment with anti-arrhythmic drugs within the previous 6 months.
Exclusion criteria
Patients with ventricular fibrillation, previous VT ablation, acute ischemia, non-ischemic cardiomyopathy, uncontrolled heart failure, left ventricular thrombus, mechanical prosthetic valves, severe peripheral vascular disease, disease process likely to limit survival to <1year, dementia or pregnancy will be excluded.
Outcome results
None listed