Effect of Cortisone on the Size of Experimentally Produced Myocardial Infarcts

Abstract

In a total of 57 dogs the anterior descending branch of the left coronary artery was doubly ligated. Cortisone apparently (1) reduced the area of residual fibrosis; (2) All animals were sacrificed 14 to 22 days after operation.In group II (18 animals), the anterior descending branch of the left coronary artery was ligated 0.5 cm. below the origin of the circumflex branch (high ligation). Nine animals were treated with cortisone, 20 mg. twice a day for 20 days, and nine animals were kept as controls. All of these animals were sacrificed 30 days after operation. They had been confined to their cages until the time of sacrifice and had received 1 cc. of procaine penicillin (300,000 units) daily postoperatively for four days. Cortisone used in these experiments was given intramuscularly and the initial dose was given immediately as the coronary artery was ligated. Electrocardiograms (standard limb leads, augmented unipolar leads and V leads) were taken before, during and after ligation of the coronary artery. Upon sacrifice of the animals the heart and lungs were exposed and photographed in situ. Then the heart and lungs were removed en bloc. The hearts were studied by means of x-ray films of the injected coronary bed by the following technic: The right and left coronary arteries were isolated and a cannula was introduced into these vessels and tied. A 20 per cent suspension of bismuth oxychloride with a 20 per cent gum acacia base was injected through the cannula under pressure varying from 80 to 120 mm. Hg.2 X-ray films were then taken of the heart ( fig. 1).After injection, the hearts of all coronary ligated animals were fixed in 10 per cent formaldehyde for three days and then sectioned serially. The

Pharmacologic modification of myocardial ischemia.

“…The epicardial ischemic area was reduced compared with postligation control (p < 0.05). Our results confirm previous reports that steroids permit an increase in coronary flow,26 27 perhaps by preventing the endothelial swelling associated with ischemia.2t 29 This increase in coronary flow and the increase in capillary oxygen tension without a corresponding increase in myocardial oxygen demand allow oxygen to diffuse farther into the ischemic zone. This was documented by an increase in the oxygen-diffusion zone (p < 0.001).…”

Reduction of Experimental Myocardial Infarct Size by Corticosteroid Administration

“…In addition, it has been demonstrated that interventions which may exert metabolic effects, such as glucose-insulin-potassium, act to protect ischemic myocardium from necrosis (4). The corticosteroid administration may have a beneficial effect on infarct size has been investigated by a number of workers, but the results have been conflicting (5)(6)(7). Since the newly developed methods for assessing myocardial ischemic injury are more sensitive and reliable than those previously available, we have undertaken to evaluate the effects of pharmacologic doses of corticosteroids on experimental infarcts.…”

Inhibiting Effect of Dexamethasone on Evolving Myocardial Necrosis in Coronary-Ligated Rats, with and without Reperfusion

“…On the one hand, findings of Johnson et al [1953] and Shatney et al [1976] in coronaryligated dogs, and Lefer et al [1980] in cats, suggest a reduction of the infarct size by cor ticosteroids. On the other hand, such an ef fect was missing in the experiments of Opdyke et al [1953] and Vogel et al [1977], Although it is an indirect indication of the salvage of ischemic myocardium, the de crease of the infarct signs in the electrocar diogram obtained with corticosteroids in dogs [Libby et al, 1973], cats [Spath et al.…”