The goal of this observational study is to determine if electrophysiologic mapping and cardiac MRI can help identify patients that have genetic forms of cardiomyopathy that are at high risk for development of dangerous ventricular arrhythmias. The investigators aim to study: 1. the prevalence and mechanism of inducible ventricular tachycardia 2. pace-mapping to define the site of origin of ventricular arrhythmias 3. voltage mapping to define low voltage scar substrate in the basal LV to determine the risk of development of ventricular arrhythmias in patients with genetic forms of cardiomyopathy. Participants will undergo cardiac MRI before their scheduled procedure and voltage mapping during their scheduled procedure as part of data collection.