The respirometer should be turned on when assessing which possible disease process(es)?

A respirometer monitors the respiratory cycle and is essential when evaluating diseases in which respiratory variation affects echocardiographic measurements, such as pericardial effusion and cardiac tamponade. In tamponade, respiratory changes in mitral and tricuspid inflows, as well as variations in inferior vena cava size, are key diagnostic features.

Congestive heart failure, ischemic cardiomyopathy, and mitral valve diseases do not require synchronization with respiration for diagnosis or quantification and are not reliant on respirometer use.

This recommendation is outlined in ASE pericardial disease guidelines and echocardiography procedural protocols【16:Textbook of Clinical Echocardiography, 6e†p.280-285】【12:ASE Pericardial Disease Guidelines†p.300-305】.