Study Objective: Researchers aim to understand why some hearts experience ventricular arrhythmias, which are unusual heart rhythms in the lower chambers. They will study the heart's electrical signals to find problem areas that might cause these arrhythmias. This research may improve results for those undergoing ventricular tachycardia (VT) ablation, a procedure to treat fast heartbeats.

Current Challenges: VT ablation is the main treatment for those whose conditions don't improve with medication. However, it often doesn't work well because it’s hard to find key areas of heart muscle causing VT. Newer methods to map the heart have not significantly increased success rates. The study will use a special tool, the MAP catheter, to better detect areas critical for treating VT. This catheter records electrical activity without disrupting standard treatment.

• Participation might involve using a special catheter during a typical VT ablation.
• Eligible participants must have a specific heart condition and an implantable defibrillator.
• Exclusion criteria include certain heart conditions and recent heart surgeries.