This study is evaluating the use of a new technique in ablation of ventricular tachycardia. During a heart procedure called an ablation, doctors must map the heart to find the small areas causing the abnormal rhythm. The study compares two different mapping methods: the standard high-density voltage mapping and a newer method called ILAM, which may help doctors find the problem areas more quickly and precisely. If you join the study, you will be randomly placed—like flipping a coin—into one of the two mapping groups during your procedure. Both methods are already FDA-approved and used for treating VT. You will also have several follow-up visits over 12 months so the study team can check your heart rhythm, device activity (if you have one), and overall health. The goal is to learn whether the newer ILAM method works better or just as well as the standard approach for treating VT.