Which pressure parameter is most closely associated with left heart pressures?

Which pressure parameter is most closely associated with left heart pressures?

• A. CVP
• B. PAP
• C. PCWP
• D. QT

Answer: (C)

Left heart preload is estimated most accurately by the pulmonary capillary wedge pressure. When a pulmonary artery catheter is advanced and the balloon is wedged in a small branch, the pressure read from that location equilibrates with the pressure in the left atrium, which closely reflects left-sided filling pressures (and, by extension, left ventricular end-diastolic pressure in a compliant heart). Central venous pressure measures right atrial pressure, so it reflects the right side. Pulmonary artery pressure reflects the pressures in the pulmonary artery and the right heart circuit, not the left heart. QT isn’t a pressure measurement. So the wedge pressure best corresponds to left heart pressures.

Left heart preload is estimated most accurately by the pulmonary capillary wedge pressure. When a pulmonary artery catheter is advanced and the balloon is wedged in a small branch, the pressure read from that location equilibrates with the pressure in the left atrium, which closely reflects left-sided filling pressures (and, by extension, left ventricular end-diastolic pressure in a compliant heart). Central venous pressure measures right atrial pressure, so it reflects the right side. Pulmonary artery pressure reflects the pressures in the pulmonary artery and the right heart circuit, not the left heart. QT isn’t a pressure measurement. So the wedge pressure best corresponds to left heart pressures.