Time Dependence of Myocardial Contractility in the Human Left Ventricle*

The timing of intrinsic contractile events has been studied in the human heart. Time to peak force averaged 69 msec in the normal heart as compared with 98 msec in patients with aortic stenosis. Contractile element velocity increased following peak force in both groups, although maintained for different durations before an abrupt deceleration occurred, probably representing decay of maximum active state.