A reproducible and stable model of acute ischaemic left ventricular failure in dogs

A model of acute ischaemic left ventricular (LV) failure is presented. In closed-chest anaesthetized dogs 50 micrometer plastic microspheres were injected repeatedly into the left main coronary artery over a period of about 40 min. The injections effected stepwise elevations of LV end-diastolic pressure (LVEDP). Thus, LVEDP could be increased to a desired level, about 20 mmHg, in a very controlled manner. All dogs developed signs of markedly depressed LV performance. Haemodynamic conditions stabilized about 60 min after embolization. The maximum LVDP/dt decreased from 2696 +/- 169 to 1823 +/- 98 mmHg . x-1, cardiac output decreased from 2.81 +/- 0.20 to 1.98 +/- 0.14 l . min-1 and mean aortic blood pressure decreased from 144 +/- 4 to 127 +/- 3 mmHg, while total peripheral resistance increased from 56 +/- 3 to 69 +/- 3 mmHg . l-1 . min. Myocardial blood flow decreased from 103 +/- 7 to 79 +/- 6 ml . min-1 . 100 g-1 and myocardial oxygen consumption decreased from 12.5 +/- 0.9 to 8.3 +/- 0.8 ml . min-1. 100 g-5. Myocardial uptake of lactate and free fatty acids decreased markedly. Electrocardiography showed signs of acute ischaemia. There were no deaths due to ventricular fibrillation. Morphological studies showed multiple small infarcts throughout the entire LV. In conclusion, repeated coronary embolization with 50 micrometers plastic microspheres, guided by the rise of LVEDP represents a simple and reproducible method for induction of uniform and stable acute LV failure.