Although numerous studies have consistently reported this isoform switch in various cardiomyopathies—including DCM, hypertrophic cardiomyopathy (HCM), ischaemic cardiomyopathy (ICM), and aortic stenosis—comparative data on MYH6/MYH7 expression ratios in healthy human LVs remain limited. Here, MYH7 is linked to familial dilated cardiomyopathy.