[Experimental study of changes in the right-sided heart hemodynamics and in the reserve force of pulmonary vascular bed after pneumonectomy].
Experimental results are reported of the characteristic impedance in the right-sided heart hemodynamics, and of the reserve force of the pulmonary vascular bed, both in the acute phase and in the chronic phase, following pneumonectomy. To investigate the difference in the reserve force of the pulmonary vascular bed between immediately after left pneumonectomy and 30 days afterward, a total of 15 mongrel dogs were divided into three groups for investigation; Group A--examined immediately after left simple thoracotomy, Group B--immediately after left pneumonectomy, and Group C--examined at 30 days after left pneumonectomy. Immediately after left pneumonectomy (Group B), both the mean pulmonary artery pressure and the total pulmonary resistance index were higher than when after only left simple thoracotomy (Group A). However, by 30 days afterwards (Group C), there was no difference between them. The right-sided heart hemodynamics were investigated by repeated infusions through the right atrium of glass beads (diameter size 100-150 microns, 50 mg/kg). In Group C, the mean pulmonary pressure and total pulmonary resistance index did not increase over that in Group B until the volume of the infusion exceeded that in Group B until the volume of the infusion exceeded that in Group B, suggesting that Group C had a large reserve force of the pulmonary vascular bed than had Group B. Furthermore, Group C revealed a significantly decreased characteristic impedance immediately after the infusion of the glass beads compared to before the infusion, but it increased later.(ABSTRACT TRUNCATED AT 250 WORDS)
Hayashida
R
R
First Department of Surgery, Kurume University School of Medicine, Japan.
D000818:Animals; D016280:Atrial Function, Right; D004285:Dogs; D006439:Hemodynamics; D010992:Plethysmography, Impedance; D011013:Pneumonectomy; D011184:Postoperative Period; D011652:Pulmonary Circulation; D011669:Pulmonary Wedge Pressure; D014655:Vascular Resistance