Preload (cardiology)

As a preload ( preload only VINYL ) is in cardiology refers to that force to stretch the fibers of the heart chambers (ventricles ) delivers at the end of diastole and is limited by the maximum idle length of the muscle fibers.

With increasing the venous filling pressure ( increase in preload ) the ventricles diastolic more filled and the muscles are stretched while stronger, which leads to an enhancement of the contraction with an increase in stroke volume ( Frank -Starling mechanism ).

In practice, the preload as the end-diastolic volume, or (less accurately ) is called the diastolic pressure in the heart. For simplicity, can be replaced by the pressure to determine the preload volume, but this does not in all situations ( eg non-elastic or rigid ventricular walls ) leads to exact measurements.

In diseases such as ( systolic ) heart failure, the preload is increased due to the increased end-diastolic volume and ventricular filling pressures. As a result, caused edema, which, in the case of pulmonary edema, leading to dyspnea. Similarly, it behaves at reduced elasticity of the ventricle ( diastolic heart failure): If the stiffer ventricle, the diastolic filling, resulting in a venous blood backflow deteriorated. The pre-load can be reduced, for example, ACE inhibitors, diuretics, or nitrates such as nitroglycerin.