Abstract: Objective: To evaluate the efficiency of a new paraaortic counterpulsation device (PACD) assist therapy in acute heart failure animal modle.Methods: Eight sheep weighing (44.9±2.5)kg were selected.PACD was made by ourself.The blood chambers were connected to descending aorta through a valveless artifical vessel,and air chambers were connected to the intra-aortic ballon pump (IABP) console.The counterpulsation therapy was fulfilled by filling air during heart systole and deflating air during heart diastole.Acute heart failure was induced in all by snaring the left anterior descending coronary artery and (or) branch of left circumflex artery.The hemodynamic effects of PACD were assessed.Hemodynamic parameters during the PACD-assisted beats were compared with those during the unassisted beats to evulate the role of PACD.Results: PACD activation increased cardiac output and mean arterial pressure by 6.29% and 2.04%,respectively,while systole aortic pressure and diastolic aortic pressure were decreased significantly by 3.67% and 8.39%,respectively.The left carotid artery blood flow was increased by 8.12% (P<0.01),and left main coronary artery blood flow was increased by 13.88% (P<0.01).In assistant beats,the peak-augmented diastolic pressure was (97.25±13.67) mmHg,exceeding of unassisted significantly (P<0.01).Conclusions: In acute heart failure model,PACD is an effective counterpulsator which decreases left ventricular afterload and increases hemoperfusion of heart and brain.