Accurate characterization of cardiac electrophysiological substrate is pivotal in cardiology for diagnosing and treating arrhythmias. The HD Grid catheter offers improved mapping capabilities, yet challenges persist in assessing tissue properties in data from swine undergone electroporation ablation. This study aims to characterize healthy and necrotic tissue using voltage amplitude and electrical propagation disorganization, using a Vector Field Heterogeneity (VFH) metric. We observed significant reductions in voltage amplitude and increases in heterogeneity post-ablation, indicating successful tissue modification. Correlations between voltage amplitude and heterogeneity underscore their complementary nature in tissue characterization, enhancing our understanding of cardiac tissue properties. This study categorized myocardial tissue using omnipolar amplitude and VFH, with healthy tissue showing high voltage and low heterogeneity, and necrotic tissue exhibiting low voltage and high heterogeneity, demonstrating their complementary nature in cardiac tissue characterization.