[Consequences of continuous positive airway pressure (CPAP) on left ventricular function. Assessment by M-mode...

The consequences of continuous positive airway pressure (CPAP) on left ventricular function are uncertain. Left ventricular function was assessed by M-mode echocardiography in 8 young normal subjects during CPAP via face mask. Heart rate and arterial pressure did not change. End-diastolic volume and stroke volume significantly decreased. Ejection fraction remained unchanged. The slight decrease of stroke volume induced by increasing positive airway pressure is in relation to decreased left ventricular preload.