Effects of respiration on right ventricular size and function: an echocardiographic study.

The effects of quiet respiration and body position on right ventricular (RV) size and function were assessed by two-dimensional (2DE) and M-mode echocardiography in 15 healthy children. All end-diastolic echocardiographic dimensions, areas, and volumes increased slightly but significantly with inspiration. At end-systole similar changes were found. RV ejection fractions were significantly higher during inspiration, as were stroke volume indices. RV dimensions also increased from supine to left lateral decubitus position. Thus, our results indicate a need for standardization of 2DE and M-mode measurements not only for body position, but also for respiratory phase when used to assess RV size and function.