Wedge pressure primarily reflects preload of which ventricle?

Wedge pressure primarily reflects preload of which ventricle?

• A. Right ventricle
• B. Left ventricle
• C. Left atrium
• D. Pulmonary artery

Answer: (B)

Pulmonary capillary wedge pressure is used to gauge left-sided filling pressures, acting as a proxy for the left atrial pressure and, by extension, the preload of the left ventricle. When the catheter is wedged in a small distal pulmonary artery, the pressure measured equilibrates with the pressure in the left atrium. Since the left atrial pressure reflects the amount of blood returning to and loading the left heart, it corresponds to left ventricular preload (LV end-diastolic pressure) under normal conditions. This is why the wedge pressure is interpreted as indicating left-sided preload rather than right-sided pressures.

Pulmonary capillary wedge pressure is used to gauge left-sided filling pressures, acting as a proxy for the left atrial pressure and, by extension, the preload of the left ventricle. When the catheter is wedged in a small distal pulmonary artery, the pressure measured equilibrates with the pressure in the left atrium. Since the left atrial pressure reflects the amount of blood returning to and loading the left heart, it corresponds to left ventricular preload (LV end-diastolic pressure) under normal conditions. This is why the wedge pressure is interpreted as indicating left-sided preload rather than right-sided pressures.