Which measurement reflects left heart preload?

Pulmonary artery wedge pressure (PAWP) serves as an important indicator of left heart preload because it reflects the pressure in the left atrium. When a catheter is wedged in a pulmonary artery, it estimates the pressure in the left ventricle at end diastole, which is directly influenced by the volume of blood returning to the heart (preload). A higher PAWP indicates increased left atrial pressure and correlates with elevated preload conditions, such as in heart failure or fluid overload states, while a lower PAWP reflects reduced preload, such as in hypovolemia or dehydration.

This measurement is vital for assessing cardiac function and guiding treatment in critically ill patients, helping to evaluate fluid status and the effectiveness of therapeutic interventions on the left side of the heart. Understanding PAWP allows healthcare providers to make informed decisions regarding fluid management and cardiac output optimization.