What is the characteristic finding in pulmonary emboli leading to right heart strain?

In the context of pulmonary embolism (PE) leading to right heart strain, increased systemic vascular resistance is an important finding. When a pulmonary embolism occurs, it obstructs blood flow in the pulmonary arteries, which leads to an increase in pressure in the right ventricle as it works harder to pump blood against the obstruction. This situation can create a scenario where the afterload on the right ventricle increases, contributing to right heart strain.

Increased systemic vascular resistance typically means that the systemic circulation is seeing a compensatory increase in resistance as the body attempts to maintain blood flow and pressure in the face of compromised pulmonary circulation. In this state, despite the primary issue being in the pulmonary circuit, the systemic circulation's response to increased resistance plays a critical role in the overall hemodynamics.

The other findings, such as increased pulmonary artery wedge pressure or increased central venous pressure, may not be consistently seen in the early phases of PE. While increased central venous pressure might be present in certain forms of heart failure, it's not a characteristic exclusive to pulmonary embolism. Cardiac output may also be reduced due to impaired right ventricular function, contradicting the idea of normal cardiac output in the context of significant right heart strain due to PE.