The effects of coronary dilator drugs upon the coronary circulation and myocardial metabolism were studied by coronary sinus catheterization in a total of 35 cases with hypertension, coronary sclerosis and various kinds of vulvular diseases.
Results thus obtained were as follows:
1) Following the intravenous administration of theophylline-ethylendiamine, both coronary blood flow (C.B.F.) and myocardial oxygen consumption (M.O.C.) increased in average 14 and 9.4 per cent respectively. Coronary arterio-sinus oxygen difference (ΔO₂) was significantly increased and myocardial oxygen extraction ratio was also elevated. In carbohydrate metabolism, glucose extraction showed tendency to increase, whereas lactate and pyruvate extraction tended to decrease. Thus, it is able to be concluded that theophylline-ethylendiamine not only dilatate coronary vascular bed, but also stimulate directly the myocardium, simultaneously.
2) After the sublinguar administration of nitroglycerine, C.B.F. and M.O.C. were decreased in parallel with diminished cardiac work, whereas C.B.F./cardiac output was increased, and additionally ΔO₂ as well as myocardial oxygen extraction ratio were decreased. Concerning the myocardial metabolism, lactate extraction increased or remained unchangable. These facts suggest that nitroglycerine have a coronary vasodilatating action and increases the myocardial oxygenation.
3) In three cases examined with papaverine hydrochloride, ΔO₂ and myocardial oxygen extraction ratio were increased and myocardial lactate metabolism was directed to the normal extraction in one case.
4) As a comparative study, the effects of high oxygen inhalation were studies in three cases. Of these, disturbed lactate metabolism were improved up to the normal extraction in two cases, indicating the improvement of the myocardial hypoxia by oxygen inhalation.