impaired muscle contractility abnormal cardiac muscle contractility decreased cardiac muscle contractility MP:0002974 MP:0005140 MPheno.ontology decreased cardiac muscle contraction impaired cardiac contractility impaired cardiac muscle contractility inability or reduced ability of the heart muscle to shorten or to develop increased tension, often measured by dP/dT max, fractional shortening (FS), velocity of circumferential fiber shortening (Vcfc), peak of aortic outflow velocity (PAV), and ventricular ejection fraction volume reduced cardiac contractility reduced cardiac muscle contractility reduced fractional shortening (FS) reduced peak of aortic outflow velocity (PAV) reduced velocity of circumferential fiber shortening (Vcfc) reduced ventricular ejection fraction volume