Standardized induction of myocardial ischaemia in the dog.

Ischaemia in the entire left ventricular wall was induced in dogs by installment of ameroid constrictors on the left anterior descending (LAD) and left circumflex (LC) branches of the left coronary artery (series A). Ischaemia in the anterior left ventricular wall was induced by installment of an ameroid constrictor on LAD and ligation of all (series B) or part of (series C) the subepicardial intercoronary anastomoses between LC and LAD. The effect of the operation was studied by electrocardiography and coronary angiography and, post mortem by radiography of the coronary arteries and histopathology of myocardium and coronary arteries. The high early mortality rate in series A and B precludes the further use of these procedures. In series C the mortality rate was low and in half of the cases lasting myocardial ischaemia of the anterior wall of the left ventricle was produced. The development of a small myocardial infarction was inevitable, but it was healed by the time the sought after state of stable myocardial ischaemia was reached.