What is the normal pulmonary capillary wedge pressure (PCWP) range?

• A. 0-4 mmHg
• B. 6-12 mmHg
• C. 4-8 mmHg
• D. 12-16 mmHg

Answer: (B)

Pulmonary capillary wedge pressure reflects the pressure in the left atrium and serves as a surrogate for left-sided filling pressures. When a balloon-tipped catheter is wedged in a small pulmonary artery, the pressure read is equilibrated with the left atrial pressure, giving a measure of LV preload.

The normal range is 6–12 mmHg. This window indicates normal left atrial pressures at rest. Values below this suggest low preload, while values above 12 mmHg point to elevated left-sided pressures, such as in left heart failure, significant mitral valve disease, or volume overload. The other ranges fall outside the normal window, either being too low or too high for typical resting left atrial pressure.