MYH14 and infarction: Variations with respect to cardiac actomyosin ATPase and myosin isozymes have been observed in the right and left ventricles during the development of myocardial infarction [43], and changes in both α-myosin and β-myosin in both ventricles due to infarction were prevented by treatment with a Ca2+ antagonist, amlodipine [44].