Objective:To observe the pathophysiological changes of dogs with open abdominal injury and seawater immersion-induced acute heart failure. Methods:Adult mongrel dogs were randomly divided into open abdominal injury+seawater immersion group (group A,n=8) and simple open abdominal injury group (group B,n=8). The cardiac rhythm,heart rate,systolic pressure,diastolic pressure,mean arterial pressure,pulmonary wedge pressure,central venous pressure,cardiac output,heart index,rennin,B-type brain natriuretic peptide (BNP),other relevant parameters and death rate were observed before and after open abdominal injury,during 2h seawater immersion,and at different time points after getting out of the water. The left ventiricular end-diastolic volume (LVEDV),left ventricular end-systolic volume (LVESV),stroke volumes (SV),and left ventricular ejection fraction (LVEF) were measured before and 4 h after injury by ultrasonic cardiogram. Results:The mean arterial pressure decreased significantly in group A from 5 min after injury to the end of the ovservation （P<0.05,P<0.01）,and that of group B had no measurable changes. The pulmonary capillary wedge pressure (PAWP) increased significantly; the central venous pressure,cardiac output,and cardiac index decreased gradually,and continued to decrease after putting out of water,which were significantly different from those of group B（P<0.05,P<0.01）. Group B had no measurable changes in PAWP,central venous pressure,cardiac output,and cardiac index before and after abdominal injury. The blood rennin and BNP levels were significantly increased in group A （P<0.05,P<0.01）and had no significant changes in group B. Conclusion:Prominent pathophysiological changes occur in rats with open abdominal injury and seawater immersion-induced acute heart failure.