Flow and myocardial microcirculation after experimental mammary-coronary bypass

The functional capacity of mammary-coronary bypass was assessed in acute dog experiments by means of electromagnetic flow measurement and estimation of myocardial flow by hydrogen polarography. 1)In the intact myocardium the central flow of the mammary-coronary bypass and the tissue perfusion provided by its correspondence to the functional capacity of the intact anterior descending coronary; 2) despite an unchanged perfusion pressure the myocardium damaged by infarction is no longer able to take up the available quantity of blood, and both flow and tissue perfusion decrease; 3) the reactive hyperaemia induced by ischaemia considerably reduces the microcirculation of the damaged myocardial tissue.