Diagnosis of Non-Compaction Cardiomyopathy Cardiac imaging (eg, echocardiography, magnetic resonance imaging with late gadolinium enhancement) Genetic testing Screening of first-degree relatives Diagnosis of non-compaction cardiomyopathy is suspected in patients with manifestations of arrhythmias or conduction disorders in whom standard evaluation (eg, echocardiography) discloses ventricular wall abnormalities including hypertrophy, distinct layers, and deep trabeculae.