Which cardiovascular condition may lead to low PAOP readings?

Low pulmonary artery occlusion pressure (PAOP) readings can occur when there is insufficient volume of blood in the circulation. A fluid volume deficit can result from various factors such as dehydration, hemorrhage, or excessive diuresis, leading to decreased venous return to the heart. This subsequently causes a reduction in the pressure measured in the pulmonary artery, reflecting the left atrial filling pressure.

In contrast, left ventricular failure typically leads to increased PAOP due to fluid backup in the lungs when the heart cannot effectively pump blood. Acute right heart failure similarly causes a rise in PAOP as the right heart struggles to move blood forward, leading to congestion. Mitral valve prolapse may also not directly lower PAOP; while it can lead to complications like regurgitation, its primary pathology doesn't typically result in low PAOP. Thus, a fluid volume deficit most directly correlates with low PAOP readings.