Myocardial anaerobic metabolism during isoprenaline infusion in a cyanotic animal model: possible cause of myocardial dysfunction in cyanotic congenital heart disease

Abstract

Mongrel dogs were made acutely cyanotic by anastamosis of the inferior vena cava to the left atrium and measurements of high fidelity left ventricular pressure, arterial pressure, blood gases, and myocardial lactate arteriovenous differences were determined before pacing, with atrial pacing at a rate of approximately 240 per minute, and during an infusion of isoprenaline to increase myocardial oxygen demands. The animals were divided into two groups on the basis of the arterial PO₂ during isoprenaline: acyanotic or control dogs (n =4, PO₂, ≥ 6.7 kPa [50 mmHg],