Grant B J, Paradowski L J, Fitzpatrick J M
Department of Medicine, State University of New York, Buffalo 14215.
J Appl Physiol (1985). 1988 Oct;65(4):1885-90. doi: 10.1152/jappl.1988.65.4.1885.
We determined the effect of perivascular electromagnetic flow probes (EMF) on pulmonary hemodynamics in acute experiments. In seven dogs placement of the EMF on the main pulmonary artery (MPA) increased pulmonary arterial pulse pressure by 25% (17.8-21.9 cmH2O, P less than 0.005) and mean right ventricular pressure by 12% (23.2-25.9 cmH2O, P less than 0.001) but did not alter heart rate, systemic blood pressure, mean pulmonary arterial pressure, or right ventricular end-diastolic pressure. This response was not abolished by local application of lidocaine to the MPA. In three cats input impedance was calculated from measurements of pressure and flow in the MPA. Impedance was calculated with flow measured using an EMF and ultrasonic volume flow probe (USF), which avoids the constraining effect of the EMF. When flow was measured with an EMF rather than a USF, there was a significant difference in the impedance spectra (P less than 0.001), but it was only apparent in the moduli greater than six harmonics. We conclude that the EMF does affect right ventricular afterload in acute experiments and alters the measured input impedance.
我们在急性实验中确定了血管周围电磁血流探头（EMF）对肺血流动力学的影响。在7只犬中，将EMF置于主肺动脉（MPA）上，可使肺动脉脉压增加25%（17.8 - 21.9 cmH₂O，P < 0.005），右心室平均压力增加12%（23.2 - 25.9 cmH₂O，P < 0.001），但不改变心率、体循环血压、肺动脉平均压或右心室舒张末期压力。局部应用利多卡因于MPA并不能消除这种反应。在3只猫中，根据MPA中的压力和流量测量值计算输入阻抗。使用EMF和超声体积流量探头（USF）测量流量来计算阻抗，这样可避免EMF的限制作用。当用EMF而非USF测量流量时，阻抗谱存在显著差异（P < 0.001），但仅在大于六次谐波的模量中明显。我们得出结论，在急性实验中EMF确实会影响右心室后负荷并改变测量的输入阻抗。
