[Hemoglobin affinity to oxygen and its correction with captopril in chronic cardiac insufficiency]

Blood gaseous composition, mechanisms controlling hemoglobin affinity to oxygen and hemoglobin effects of a single captopril dose were assessed in 124 patients with chronic heart failure (CHF). CHF-associated hypoxemia was shown to be mixed, with the circulatory component prevailing. Hemoglobin affinity to oxygen is increased in CHF, stage IIA, and reduced in CHF, stages IIB-III. 2,3-diphosphoglycerate is the principal regulator of hemoglobin affinity to oxygen its blood level increasing progressively as CHF aggravates. Hemoglobin affinity to oxygen may be reduced by captopril in patients with CHF of stages I-IIA.