What is pulmonary vascular resistance (PVR)?

Pulmonary vascular resistance (PVR) is defined as the resistance that the right ventricle needs to overcome in order to pump blood through the pulmonary circulation, which involves the lungs. This resistance is crucial because it affects how efficiently the right heart can function and how much effort it needs to exert to maintain adequate blood flow and oxygenation of the blood.

High levels of PVR can lead to strain on the right ventricle, potentially resulting in conditions such as right heart failure if the resistance is significantly elevated. Understanding PVR is essential for evaluating and managing patients with heart conditions, including those with heart failure, as it relates to the overall hemodynamic status and the performance of the right side of the heart.

The other options do not accurately define PVR. The pressure in the left atrium relates to the left ventricular and systemic circulation, heart rate variability measures variations in heart rates rather than resistance, and systemic blood pressure pertains to the left side of the circulatory system, indicating that these choices do not reflect the specific meaning and implications of pulmonary vascular resistance.