Dynamic Voltage Mapping to Personalise the Ventricular Tachycardia Substrate

Ventricular tachycardia (VT) is a life-threatening heart rhythm disorder and one of the commonest causes of heart-related sudden death. It often affects people who have had a heart attack or other structural heart damage. VT occurs when abnormal electrical circuits develop within and around scar tissue in the heart. People at risk are usually offered an implantable cardiac defibrillator (ICD), a device that can detect VT and deliver a lifesaving shock. While effective, these shocks can be sudden, painful and distressing. Medications such as amiodarone can also help, but they are often unsuitable for long-term use due to their potential side effects on the liver, lungs and thyroid gland. An alternative is catheter ablation. Thin tubes (catheters) are threaded from a blood vessel in the groin to the heart, allowing the cardiologist to identify scar tissue and abnormal electrical circuits, which can be destroyed using heat, freezing or electrical energy. Although ablation can help many patients, VT can return in up to one in three people after the procedure. This is because it can be difficult to precisely identify the scar and surrounding tissue that sustain the abnormal circuits, making it challenging to know exactly where to apply ablation treatment. Dynamic Voltage Mapping, is a technique which the investigators believe can more accurately identify scar and the critical bordering tissue during ablation. Initial data collected suggests that the approach accurately predicts the VT circuit and helps guide ablation. In this study, the investigators wish to recruit 40 participants undergoing VT ablation to determine how effective Dynamic Voltage Mapping is in real-world procedures.