Journal of Applied Physiology, Vol 65, Issue 4 1885-1890, Copyright © 1988 by American Physiological Society
Effect of perivascular electromagnetic flow probes on pulmonary hemodynamics
B. J. Grant, L. J. Paradowski and J. M. Fitzpatrick
Department of Medicine, State University of New York, Buffalo 14215.
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.
