Acute Myocardial Ischaemia in Anaesthetized Cats: Effects of Papaverine

Abstract

1 The effects of papaverine on coronary blood flow, myocardial oxygen consumption, myocardial oxygen tension and the ischaemic ECG pattern were studied in anaesthetized open-chest cats representing three models of acute coronary insufficiency: ligation, spasm, and perfusion of the coronary artery at a stabilized insufficient level. 2 Despite the increase in myocardial oxygen consumption reflecting elevation of oxygen demand, papaverine improved the signs of myocardial ischaemia (the myocardial oxygen tension and ECG pattern), as long as there was a possibility of an increase in blood supply to the affected zone. Where this was excluded, the symptoms were actually aggravated. 3 The results suggest that there is no basis for dividing coronary dilators into 'benign' and 'malignant' according to their ability to increase myocardial oxygen requirements. A coronary dilator enhancing oxygen demand may prove beneficial even following complete coronary artery occlusion.

The effect of exaprolol (MG 8823) on epicardial ST‐segment changes in a feline model of acute myocardial ischaemia

“…The site of occlusion and anaesthetic used are two major factors determining the severity of early ischaemic arrhythmias (Marshall & Parratt, 1980). The other groups using a pentobarbitoneanaesthetized cat model similar to our own (Lefer, Cohn & Osman, 1977;Kisin, 1978) do not mention ventricular arrhythmias occurring after LAD occlusion; presumably these were not serious.…”