MYOCARDIAL CITRATE METABOLISM OF HUMAN HEART STUDIED BY CORONARY SINUS CATHETERIZATION

Abstract

The myocardial citrate metabolism was investigated coronary sinus catheterization in 49 human subjects, including 8 healthy individuals, 6 hypertensive patients without ST-T abnormalities in electrocardiogram (Group I), 16 hypertensive patients with abnormal ST-T findings (Grou II), 9 patients with coronary sclerosis with normal blood pressure and abnormal ST-T findings, 5 patients with mild congestive heart failure due to various kinds of valvular diseases, 4 anemic patients and one thyrotoxic case. Studies were performed at resting state and effects of vasoacting drugs were observed. The drugs examined were vasopressors as norepinephrine and epinephrine, antihypertensive drugs as hexamethonium and hydralazne, coronary dilating drugs as nitroglycerine, papaverine and theophylline-ethylendiamine, and high oxygen tension. The results obtaind were as follows. 1. In the healthy individuals, the average arterial citrate concentration (Ca) was 0.87±0.18mg per 100ml, the coronary venous citrate concentration (Cs) 0.65±0.11mg per 100ml. and the coronary arterio-venous citrate difference (ΔC) 0.20±0.13mg per 100ml/ Cs and ΔC tended to vary with arterial lavel and the relationship of the Cs or ΔC to Ca was demonstrated by the following thentative formula. Cs=0.44Ca+0.27; ΔC=0.56Ca-0.27 2. In patients with hypertension, coronary sclerosis, or mild congestive failure, myocardial citrate extraction was decreased or negative, showing a significant fifference from mormals, Similar tendency, theough statistically not significant, wsa seen also in anemia and thyrotoxicosis. 3. When the blood pressure was elevated in healithy cases by intravenous drop infusion of epiephrine, it was noticed that the relationship between Ca and Cs showed a beviation from that of mormals. In contrast, myocardial citrate metabolism of hypertensive hearts tended to be normalized by slow intravenous in jection of antihypertensive durgs such as hexamethonium or hydralazine. 4. As coronary dilating drugs, the effects of nitroglycerine administered sublingually and papaverine and theophyllin-ethylendiamine given intravenously were examined. It was clarified the, as the effects on the myocardial citrate metabolism were concerned, each drug had different action; disturbance of myocardial citrate metabolism was improved by nitroglycerine of papaverine, whereas it was aggravated by theophylline-ethylendiamine. 5. By inhalation of 50 or 100% oxygen, the disturbance in citrate metabolism was improved. 6. In patients with hypertension, sopontaneous blood pressure variation was reflected on the change of myocardial citrate metabolism. 7. From the above described data, it was concluded that the disturbance of citrate metabolism was present in the heart muscle of patients not only with hypertension, coronary sclerosis, & congestive failure, but with anemia and thyrotoxicosis, and that it might be resulted from the sequel of hypoxia in myocardium.