After a cardiomyoplasty, collaterals from skeletal muscle form to chronic ischemic myocardium.

We measured the collateral formation between skeletal muscle and the heart after a latissimus dorsi cardiomyoplasty in an animal model that contained normal, chronic ischemic, and infarcted myocardium. The area at risk for ischemia was 27.0 +/- 3.2% of the left ventricular mass (n = 10, mean +/- SE). In five animals the risk area developed predominantly into chronic ischemic myocardium; in five others the risk area became an infarct. The collateral blood flow from the skeletal muscle to chronic ischemic myocardium (6.05 +/- 1.36 ml/100 g/min, n = 5) was higher than flow to the infarct (0.46 +/- 0.31 ml/100 g/min, n = 5). The collateral blood flow to normal myocardium was minimal (0.04 +/- 0.01 ml/100 g/min). The collateral blood flow appeared to be concentrated in the outer half of the left ventricular wall, with the epicardium having a higher skeletal muscle derived collateral blood flow than endocardium (p < 0.05). We conclude that after a cardiomyoplasty a collateral blood flow, which approaches clinical significance, is preferentially established between skeletal muscle and chronic ischemic myocardium. Enhancement of this collateral blood flow might provide a means to revascularize patients with presently inoperable coronary disease.