What does a Swan-Ganz catheter primarily measure?

A Swan-Ganz catheter is primarily utilized in clinical settings to measure pulmonary artery pressures and assess cardiac function, specifically focusing on right heart pressures and pulmonary artery wedge pressure (PAWP), which reflects left atrial pressure.

While a Swan-Ganz catheter can indirectly provide insight into left ventricular preload through the measurement of left atrial filling pressure, its primary function is broader than just measuring preload. The PAWP is often used clinically to estimate left ventricular diastolic pressure, and by extension, preload, which is a critical concept in managing various cardiac conditions.

In contrast to left ventricular preload measurement, the Swan-Ganz catheter also obtains direct measurements like right ventricular pressure and cardiac output, along with estimating blood oxygen levels with the help of additional devices and calculations. However, the emphasis of the Swan-Ganz catheter’s design and primary function typically revolves around the assessment of cardiac performance and hemodynamic monitoring, particularly in critically ill patients.

The other options, while related to functions of the Swan-Ganz catheter, do not directly encapsulate its primary purpose as effectively as the measurement of left atrial filling pressure, which is pivotal in understanding the hemodynamic status in the context of heart function.