THE IMMEDIATE EFFECTS OF THE OCCLUSION OF THE CORONARY VEINS ON THE DYNAMICS OF THE CORONARY CIRCULATION

Abstract

The phasic changes in venous pressure, peripheral coronary pressure and arterial inflow in the heart were studied by optical methods before and after acute cardiac venous ligation (coronary sinus or great cardiac vein). The intraven. pressure rises from control values of about 10/2 mm. Hg to figures which during systole approach or exceed the aortic systolic and whose diastolic value rises to 20-40 mm. Hg. The peripheral coronary pressure, simultaneously recorded, is elevated in the left coronary in like degree and has a contour and time relation similar to the venous pressure, although its ordinate values are generally slightly less. Probable explanations for these changes in venous and peripheral coronary pressure are advanced. The arterial inflow into the left coronary is reduced considerably, while that into the right coronary is presumably not affected. Since the left coronary inflow does not approach zero and the myocardium still contracts, there must be potent drainage channels still remaining. These are presumably venous, since if a left coronary ramus is now occluded the myocardium fails to contract even if the peripheral coronary is allowed to bleed. Since acute cardiac venous ligation does not prevent failure of contraction in a myocardial area whose coronary has been ligated and does reduce materially the left coronary arterial inflow, such a procedure cannot be regarded as a method of choice for encouraging the blood supply to such a potentially in-farcted area.