Anterior left ventricular wall circulation in patients with coronary artery disease

The human anterior left ventricular circulation was investigated at rest and during submaximal atrial pacing by measuring the great cardiac venous blood flow by the constant infusion thermodilution method. Forty-seven patients with angina pectoris participated in the study and were grouped stepwise according to degree of arteriosclerosis in the left anterior descending coronary artery (LAD), from normal to occluded vessel. Special attention was paid to patients with earlier infarcts and to collateral circulation.Blood flow to the myocardium was slightly but significantly reduced only among patients with a subtotal stenosis of the LAD without demonstrable collateral circulation, and only during atrial pacing. This conforms with an increased coronary arteriolar resistance in these patients. Myocardial oxygen extraction was, however, increased in all groups of patients with LAD stenosis from 50% to occlusion, except in patients with an earlier anterior wall myocardial infarction. This suggests a disproportio...