Hemisystole

n. (Physiol.) Contraction of only one ventricle of the heart. [ 1913 Webster ]

☞ Hemisystole is noticed in rare cases of insufficiency of the mitral valve, in which both ventricles at times contract simultaneously, as in a normal heart, this condition alternating with contraction of the right ventricle alone; hence, intermittent hemisystole. [ 1913 Webster ]