Pulmonary capillary wedge pressure is an indirect measure of pressure in which side of the heart?

Pulmonary capillary wedge pressure is an indirect measure of pressure in which side of the heart?

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

Answer: (C)

Pulmonary capillary wedge pressure reflects the pressure in the left atrium. When a balloon-tipped catheter is threaded into a small branch of the pulmonary artery and the balloon is inflated to wedge, the pressure measured beyond the occlusion is transmitted back through the pulmonary capillary bed to the left atrium. In this state, the readout approximates left atrial pressure (and thus left-sided filling pressures, and often LV end-diastolic pressure under certain conditions). It does not measure right atrial or right ventricular pressures directly, and it is not a direct measure of left ventricular systolic pressure.

Pulmonary capillary wedge pressure reflects the pressure in the left atrium. When a balloon-tipped catheter is threaded into a small branch of the pulmonary artery and the balloon is inflated to wedge, the pressure measured beyond the occlusion is transmitted back through the pulmonary capillary bed to the left atrium. In this state, the readout approximates left atrial pressure (and thus left-sided filling pressures, and often LV end-diastolic pressure under certain conditions). It does not measure right atrial or right ventricular pressures directly, and it is not a direct measure of left ventricular systolic pressure.