Selective ECG synchronised suction and retroinfusion of coronary veins: first results of studies in acute myocardial ischaemia in dogs

Abstract

The aim of the study was to test an intermittent ECG synchronised suction device which was added to a coronary vein retroinfusion system (selective suction and retroinfusion = SSR) in order to transport oxygenated fluid more efficiently into ischaemic myocardium. The suction period preceding the retrograde pumping period was sufficient to allow the coronary veins to empty upstream of the retroinfusion catheter tip, thus facilitating the refilling of the veins by the retrogradely pumped oxygenated fluid. Subepicardial oxygen partial pressure measurements and determination of post mortem infarct size were used to study the efficacy of SSR treatment in an open chest infarct model. 15 beagle dogs were subjected to occlusion of the left anterior descending coronary artery for up to 5 h. Using oxygenated Ringer lactate solution for SSR treatment (given 30 min to 5 h after occlusion of the left anterior descending artery), mean subepicardial PO2 in the ischaemic myocardium of SSR treated dogs increased by 7-12 mm Hg. Mean infarct size was reduced to 5.6(SD 3)% of left ventricle in SSR treated dogs (n = 4) compared to 27(14)% in controls (n = 4). Expressed as percent of volume at risk, mean infarct size was reduced by 84% in SSR treated dogs. These data suggest that intermittent suction increased the efficacy of coronary venous retroinfusion in acute myocardial ischaemia.