Negative wave reflections in pulmonary arteries

Ellen H. Hollander, Jiun-Jr Wang, Gary M. Dobson, Kim H. Parker, John V. Tyberg
2001 American Journal of Physiology. Heart and Circulatory Physiology  
Negative wave reflections in pulmonary arteries. Am J Physiol Heart Circ Physiol 281: H895-H902, 2001.-The pulmonary arterial branching pattern suggests that the early systolic forwardgoing compression wave (FCW) might be reflected as a backward-going expansion wave (BEW). Accordingly, in 11 openchest anesthetized dogs we measured proximal pulmonary arterial pressure and flow (velocity) and evaluated wave reflection using wave-intensity analysis under low-volume, high-volume, high-volume ϩ 20
more » ... high-volume ϩ 20 cmH 2O positive end-expiratory pressure (PEEP), and hypoxic conditions. We defined the reflection coefficient R as the ratio of the energy of the reflected wave (BEW [Ϫ]; backward-going compression wave, BCW [ϩ]) to that of the incident wave (FCW [ϩ]). We found that R ϭ Ϫ0.07 Ϯ 0.02 under low-volume conditions, which increased in absolute magnitude to Ϫ0.20 Ϯ 0.04 (P Ͻ 0.01) under high-volume conditions. The addition of PEEP increased R further to Ϫ0.26 Ϯ 0.02 (P Ͻ 0.01). All of these BEWs were reflected from a site ϳ3 cm downstream. During hypoxia, the BEW was maintained and a BCW appeared (R ϭ ϩ0.09 Ϯ 0.03) from a closed-end site ϳ9 cm downstream. The normal pulmonary arterial circulation in the open-chest dog is characterized by negative wave reflection tending to facilitate right ventricular ejection; this reflection increases with increasing blood volume and PEEP. lung; hemodynamics Address for reprint requests and other correspondence:
doi:10.1152/ajpheart.2001.281.2.h895 pmid:11454596 fatcat:ykhnsebvwrckjcw55wx7qlaa2q