Left ventricular assistance is an effective treatment to lower output syndrome after cardiac surgery, postinfarction cardiogenic
shock and acts as a bridge to heart transplantation. However, there are still some problems waiting for further research, such as thrombosis, embolism, hemolysis, bleeding, infection and so on. ln this research, a new left ventricular assist device, Luo-Ye pump, was used to evaluate its antithrombosis and hemodynamic propertites. Methods: The pump was used for ten sheep(weight: 30-53Kg, mean 43.5Kg). The work condition of the pump was: driving pressure 20-25kPa, vacuum pressure 0.1-0.3 kPa, systole / diastole ratio 0.30-0.50, stroke frequency 60-70 beat/ min. results: 1.Before LVAD
bypass and after LVAD bypass 6 hours, the average blood pressures were 13.3± 0.80 kPa and 13.6 ±1.9 kPa, the CVP were 1.73±1.4kPa and 0.82±0.3kPa respectively; 2.Before LVAD bypass and after LVAD bypass 6 hours, the ventricle diameter of long axis were 5.81 ±1.9mm and 39.3 ±1.5 mm, diameter of short axis were 25.0 0132± 1.2 mm and 18.1 ± 1.4mm respectively 3. The arterial blood gas analysis showed normal before and after bypass; 4.There were no thrombus in the pumps and no embolism phenomenon in sheep kidneys identified by pathologic analysis; 5.ACT and PT were controlled to normal level after bypass 2 to 3 hours. 6.After bypass, the plasma free
hemoglobin level of postbypass was higher than the level of prebypass, and the plasma free hemoglobin reached the highest level, 224.5 ±40.8mg /L after bypass 6 hours. Conclusions: All these results show Luo-Ye Pump has good antihrombosis and hemodynamic properties. The plasma free hemoglobin level is under the permission of LVAD although it increases somewhat, Lun-Ye Pump will be an excellent left ventricle assist device.