The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.

The pre-ejection period (PEP) has recently been described as a potential parameter for monitoring cardiac preload. This study further investigated the influence of changes in intravascular volume status and the application of positive end-expiratory pressure (PEEP) on the pre-ejection period. In ten pigs, ECG, arterial pressure and stroke volume derived from an aortic flowprobe were registered.