Which of the following is commonly evaluated by the sniff maneuver?

Comprehensive and Detailed Explanation From Exact Extract:

The sniff maneuver is commonly used in echocardiography to assess right atrial pressure (RAP) indirectly by observing changes in the size and collapsibility of the inferior vena cava (IVC). During a sniff or rapid inspiration, negative intrathoracic pressure normally causes the IVC to collapse. The degree of IVC collapse during the sniff test correlates with RAP.

If the IVC is dilated and fails to collapse significantly with a sniff, this suggests elevated right atrial pressure, which can be caused by right heart failure, pulmonary hypertension, or volume overload.

This maneuver is not used to evaluate left atrial pressure or outflow tract obstructions, which require other echocardiographic parameters.

This assessment method is described in the "Textbook of Clinical Echocardiography, 6e", Chapter on Right Heart Evaluation and Hemodynamics【20:300-305†Textbook of Clinical Echocardiography】.