STUDIES ON MYOCARDIAL METABOLISM WITH SPECIAL REFERENCE TO INVESTIGATION OF pH, O2 AND CO2 TENSION IN ARTERIAL AND CORONARY VENOUS BLOOD
1957 Volume 46 Issue 9 Pages 1153-1164
Details
1957 Volume 46 Issue 9 Pages 1153-1164
1) By coronary sinus catheterization, oxygen and carbon dioxide tension of arterial and coronary venous blood were investigated in 8 normal subjects and 46 patients, including 15 patients with cardiac failure, 9 with coronary sclerosis, 4 with hypertension, 9 with hyperthyroidism, 7 with anemia and 2 with beri-beri, at resting stase, in the exercise test, in 10% oxygen hypoxia test, and after administration of drugs (digitalis preparations and theophylline-ethylendiamine).
2) The oxygen tension of the coronary venous blood seems to reflect exactly the myocardial oxygen tension. It is almost constant in normal snbjects ranging from 20.0mmHg to 24.0mmHg, with an average 21.8±0.9mmHg, but it fell remarkably in the moderate or severe cardiac failure with an average 14.2±5.9mmHg, slightly in the mild cardiac failure with an average 18.2±1.9mmHg, and in some cases with coronary sclerosis and hyperthyroidism, it fell also below the normal range; suggesting the presence of myocardial hypoxia in these patients.
3) The coronary veno-arterial pressure gradint of carbon dioxide (ΔPCO2) may be also used to presume the state of coronary circulation. It averaged in normal subjects 10.7±1.7mmHg, while it decreased markedly in anemia with an average 7.7±1.2mmHg, and in hyperthyroidism with an average 6.1±1.3mmHg, which suggests the largely increased coronary blood flow.
4) The coronary arterio-venous difference of pH ranged in normal subjects from 0.02 to 0.04 with an average 0.030±0.002, but some of cases with severe cardiac failure and with coronary sclerosis show increased difference of pH.
5) The coronary arterio-venous buffer base difference was within the range of technical error both in normal subjects and patients.
6) In the exercise test, oxygen tension of coronary venous blood shows little or no cdange both in normals and in patients. ΔPCO2 increased in normal subjects, but it decreased in a casd with coronary sclerosis and a case with congestive heart failure, suggesting that in some cardiac patients the coronary blood flow may increase in the exercise more largely than in normal subjects.
7) In the 10% oxygen hypoxia test, oxygen tension of coronary venous blood fell below the normal range at rest, both in normals and in patients. ΔPCO2 decreased in normals and the cases with anemia, but it increased in a case with coronary sclerosis, in which case ΔpH also increased largely.
8) On patients with cardiac failure, acetyl-digitoxin, lanatocide C, and theophyllin-ethylenediamine were administrated. Of the effects of digitalis, we could not get definite results, but in all cases of theophyllin-ethylene diamine, there was a fall of oxygen tension of coronary venous blood.
