einddiastole

End-diastole, or einddiastole, is the phase of the cardiac cycle at the end of diastole when the ventricles have completed filling with blood and are ready to begin contraction. It marks the moment just before ventricular systole, after atrial contraction has aided ventricular filling. The ventricular volume at this point is called the end-diastolic volume (EDV), and the corresponding pressure is the end-diastolic pressure (EDP).

The EDV represents the maximal volume the ventricles hold during a heartbeat and is a key determinant of stroke volume through the Frank-Starling mechanism: greater filling (within physiological limits) stretches cardiac muscle fibers more and increases the amount of blood ejected with the next contraction. Stroke volume equals EDV minus the end-systolic volume (ESV), and cardiac output is stroke volume multiplied by heart rate. EDV is influenced by venous return, filling time (which is affected by heart rate and rhythm), and ventricular compliance.

Clinically, EDV and the related filling pressures provide information about preload and diastolic function. EDV can be estimated noninvasively with echocardiography or cardiac MRI, and in invasive settings it is read from pressure-volume loops. Pathologies affecting einddiastole include conditions that alter preload or ventricular compliance. In hypovolemia, EDV decreases, reducing stroke volume. In diastolic dysfunction or heart failure with preserved ejection fraction, filling pressures like EDP may be elevated despite a normal or near-normal EDV, reflecting impaired ventricular compliance.