- Hemisystole Hem`i*sys"to*le, n. (Physiol.)
Contraction of only one ventricle of the heart.
Note: 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]
The Collaborative International Dictionary of English. 2000.