Primary pulmonary hypertension--a study of disturbances in circulatory hemodynamics and ventilatory function of the lungs.

Investigations of the hemodynamics of pulmonary circulation, right and left heart venticle and ventilatory function of the lungs were carried out in a group of 12 patients with primary pulmonary hypertension. The results were discussed in the light of data obtained in a group of 16 patients with chronic cor pulmonale syndrome and 16 healthy subjects. It was found that patients with primary pulmonary hypertension show a markedly raised pressure in the pulmonary artery mean pressure x = 60.3 +/- 24.2 mm Hg, in the right ventricle (systolic pressure x = 90.6 +/- 27.9 mm Hg, end-diastolic pressure x = 11.7 +/- 4.3 mm Hg), very high total pulmonary vascular resistance (x = 1571 +/- dynes. sec. cm-5) and increased work of right ventricle (x = 2.3 +/- 1.5 kgm/min/m2). In patients with chronic cor pulmonale syndrome the load on the right ventricle was much lower. The indices determining left ventricle function as a pump indicated that this function was impaired, with lower cardiac index (x = 2.1 +/- 0.8 1/min/m2), stroke volume (x = 41.7 +/- 17.2 ml) and left ventricular work (x = 2.7 +/- 1.1 kgm/min/m2). These changes might, however, be due also to impaired blood flow into the left ventricle. In contrast to patients with chronic cor pulmonale syndrome, the indices of ventilatory function of the lungs were normal or only slightly decreased. No significant correlations were observed between hemodynamic indices of pulmonary circulation and right ventricle and the parameters of the ventilatory function of the lungs.