Wave intensity analysis of right ventricular and pulmonary vascular contributions to higher pulmonary than aortic blood pressure in fetal lambs

Abstract

Although fetal pulmonary trunk (PT) blood pressure may exceed aortic trunk (AoT) pressure, the specific mechanism(s) underlying this pressure difference remain undefined. To evaluate the potential role of ventricular and vascular factors in the generation of a fetal PT-AoT pressure difference, nine anesthetized late-gestation fetal sheep were instrumented with PT and AoT micromanometer catheters to measure high-fidelity pressure and transit-time flow probes to obtain blood velocity. The PT-AoT instantaneous pressure difference (IPDPT-AoT) was calculated from PT and AoT pressure profiles. PT and AoT wave intensity (WI) was derived from the product of the appropriate pressure and velocity rate..