Key Points
- This research aims to reassess wave reflection in pulmonary arteries of healthy sheep using wave intensity analysis.
- Conducted wave intensity analysis on 12 anesthetized open-chest sheep.
- Simultaneously measured pulmonary arterial pressure and velocity.
- Calculated wave reflection at different sites along the pulmonary artery.
- Normal pulmonary arterial wave speed was measured at 2.1 ± 0.3 m/s.
- Only 1% of incident wave energy was reflected as a backward expansion wave.
- A fixed closed-end reflection from the microcirculation resulted in 2% reflection as a backward compression wave.
Structured PICO
PPopulation12 healthy adult Polworth-Comeback cross sheep (7 males; weight 41.1 ± 5.8 kg)
IInterventionWave intensity analysis (WIA) using simultaneous acquisition of proximal pulmonary arterial pressure and velocity
OOutcomePulmonary arterial wave speed and patterns of wave reflection (forward and backward-travelling waves)surrogate
In healthy sheep, the pulmonary artery exhibits minimal wave reflection characterized by variable proximal open-end reflection and fixed closed-end reflection, providing a physiological baseline for identifying early pulmonary vascular disease.
Limitations
- Use of anesthetic agents that have negative inotropic effects and induce systemic vasodilatation
- Dissection of the adventitia in the proximal pulmonary artery may affect autonomic control
- Cuff-type flow probe may have constricted or minimized normal pulsatile distension
- Assumption that the pulmonary artery was circular and cross-sectional area was constant
- Assumption that wave speed is constant throughout the cardiac cycle