[Effect of coronary bypass surgery on myocardial pressure and ventricular function in the dog]

In 7 dogs a severe stenosis of the left circumflex coronary artery (CCA) is produced in the course of 18 days. The influence of myocardial revascularization on left ventricular function and on intramyocardial pressures in the areas supplied by the CCA and by the left anterior descending coronary artery is studied. Neither under control conditions nor during acute left ventricular pressure load does opening a bypass graft between the carotid artery and CCA induce a significant change in total ventricular function (dp/dtmax, Vmax, left ventricular enddiastolic pressure). However, immediately after opening the graft intramyocardial pressure rises in the CCA area indicating a regional improvement of myocardial function.