Seventeen dogs with evolving myocardial infarctions were treated with an internal mammary artery implant in the ischemic area of the heart. The survival rate in these dogs was significantly higher than that in a control group. Improved survival was probably due to flow of arterial blood from the implant into the ischemic region. Local perfusion within the area of ischemia may have been through the myocardial sinusoids.
In a second series of dogs, no significant changes in local myocardial oxygen pressure (Po2) and temperature could be demonstrated in the ischemic perfused area when implant flow was varied. The failure to demonstrate these changes may have been due to inappropriate instrumentation or to the choice of Po2 and temperature as a measure of changes in local perfusion.