Henrik Lagerlöf

Pulmonary and renal circulatory adjustments to the upright posture in patients with mitral valvular disease

Abstract 1.1. Ten patients with mitral valvular disease were investigated in the recumbent and in the erect posture (tilted 60 degrees head up). The cardiac output, pulmonary and systemic pressures, cardiopulmonary and total blood volumes, and renal clearances of inulin and para-aminohippurate, as well as the excretion of sodium, were determined. 2.2. In 7 patients without symptoms and signs of right heart failure the cardiac and stroke outputs decreased, as well as the pulmonary capillary and the right atrial pressures. In 2 patients with clinical signs of right heart failure the cardiac and stroke outputs remained unaltered. 3.3. The pulmonary arterial pressure fell moderately when the patients took the erect posture. The pulmonary arterial and the systemic arterial pulse pressures were generally diminished. 4.4. The cardiopulmonary blood volume fell in 3 instances. This was reflected by a concomitant decrease in pulmonary capillary venous pressure. 5.5. The renal clearance of inulin and paraaminohippurate as well as the excretion of sodium generally decreased. 6.6. One patient was tilted 30 degrees head down. No symptoms appeared, and no major hemodynamic change was recorded. 7.7. The results are discussed in view of possible hemodynamic factors that may cause orthopnea in heart disease.