the usual rhythmic contraction of the heart, esp. of the ventricles, following each dilatation (diastole), during which the blood is driven onward from the chambers
The rhythmic contraction of the heart, especially of the ventricles, by which blood is driven through the aorta and pulmonary artery after each dilation or diastole.
Origin: Greek sustolē, contraction, from sustellein, to contract; see systaltic .