EFFECT OF ACETYLCHOLINE INFUSION UPON CARDIAC DYNAMICS IN PATIENTS WITH PULMONARY EMPHYSEMA

Abstract

Acetylcholine was continuously infused into the pulmonary arteries of patients with pulmonary emphysema and varying degrees of pulmonary artery hypertension. In 18 patients studied at rest, the drug produced a significant fall of 4 mm. of Mg in the mean pulmonary artery pressure. The cardiac output and minute ventilation were unaltered in 13 patients in whom these data were determined, but the total pulmonary vascular resistance fell significantly, 69 dynes-second/cm-5. The systemic saturation fell 3.1% in 14 patients. In 14 patients who were subjected to exercise and infusion the pulmonary artery mean pressure fell in all, averaging 6 mm. of Mg for the group. The mean total pulmonary vascular resistance in the 11 patients in whom this value was calculated fell 60 dynes-second/cm-5. The cardiac output, minute ventilation, and systemic pressure in these patients were also essentially unaffected by the drug infusion.