Dynamic characterization and hemodynamic effects of pulmonary waves in fetal lambs using cardiac extrasystoles and beat-by-beat wave intensity analysis

Abstract

Steady-state wave intensity (WI) analysis indicates that characteristic mid-systolic falls in fetal pulmonary trunk (PT) and artery (PA) blood flow are due to an extremely large backward-running compression wave (BCWms) that 1) originates from the pulmonary microvasculature by a combination of cyclical pulmonary vasoconstriction and vascular reflection of the forward-running compression wave (FCWis) associated with impulsive right ventricular ejection, and 2) is transmitted into the PT. However, no information is available about the dynamic properties of PA BCWms and its contribution to beat-to-beat regulation of pulmonary hemodynamics. Accordingly, beat-by-beat WI analysis was performed dur..