In a healthy individual, the PAOP/PAWP should be higher or lower than the PAD?

In a healthy individual, the pulmonary artery occlusion pressure (PAOP) or pulmonary artery wedge pressure (PAWP) is typically lower than the pulmonary artery diastolic pressure (PAD). The PAOP/PAWP reflects the left atrial pressure and indirectly estimates left ventricular end-diastolic pressure, whereas PAD is indicative of the pressure in the pulmonary artery during diastole.

In a normal physiological state, pressures in the pulmonary artery (PAD) are generally higher than those in the left atrium (PAOP/PAWP) because the left atrium serves as a receiving chamber for the blood coming from the lungs and does not exert as much pressure as the arteries. This pressure gradient is important as it allows for proper filling of the left ventricle and effective cardiac output. Deviations from this relationship can indicate various pathophysiological states, such as heart failure or increased pulmonary vascular resistance.