Abstract
With an increasing interest in cor pulmonale, several factors influencing pulmonary hemodynamics have been investigated by many authors. Most of these authors have estimated the ventricular mechanical effect from minute mean value of both systolic and diastolic phases of the cardiac cycle. however, considering the fact that the maximum ventricular mechanical effect is performed at the ejection period during the systole and more particularly during the period when the semilunar valvular open, the measurement of the accurate ventricular mechanical effect should be obtained during the ejection period rather than during both systolic and diastolic phases as in previous works. In the present study, the author used three different vasopresser agents and analyzed various phases of pulmonary circulation. From these results, ejection time of the right ventricle, mean pulmonary pressure per ejection phase and the mechanical effects of the ejection were obtained and were compared with the results of previously described methods. Material and Method A total of 24 cases was used in this study including 3 cases of normal individuals, 16 cases of cardiacs, 4 with pulmonary diseases and one with hepatic disorder. A routine right heart catheterization was carried out with a double lumen catheter. The pressures of the right ventricle and pulmonar artery were measured with simultaneous recordings of both electrocardiogram and phonocardiogram. The subjects were divided into 2 groups according to their resting mean pulmonary arterial pressure. The group I of 11 cases showed their mean pressure not exceeding 11 mmHg, the group II, consists of 13 cases with mean pressure exceeding 18 mmHg. The blood gas analysis was carried out by the method of VAN SLYKE-NEIL and expired air was analyzed with SCHOLANDER'S gas analyzer. Cardiac output was measured by FICK'S method. The control pressure as first measured during room air breathing without drugs and the second measurement was carried out 15 to 20 minutes namely, 7-chlor-ethyl-theophylline (Cl. E. T.) intravenously (200 mg), 1.4 : 3.6-dianhy-drosorbitol-2.5-dinitrate (I. S. D. N.) sublingual (10 mg) and inhalation of 50 per cent O2, and following measurements were made.
