[Evaluation of heart function in heart failure rat model by echocardiography]

To detect variation in cardiac function in heart failure rat model by echocardiography, and to explore the relationship between cardiac function and blood serum B-type natriuretic peptide (BNP).

A total of 120 two-month-old male SD rats (body mass 200 approximately 220 g) were randomly assigned to 3 groups: an operation group (80 rats) had thoracotomy, with open pericardium and ligature of the anterior descending branch of the left coronary artery; a sham operation group (20 rats) had thoracotomy and open pericardium but no ligature of the artery; and a normal group (20 rats) had no treatment. We observed the general state of the rats every day after the operation, and we measured the rats' body mass the day before the operation and at the end of 6th week after the operation. To evaluate the change of heart function in heart failure rats, echocardiography was used to detect the level of BNP after the operation.

The operation group that survived showed obvious objective sign of heart failure about 10 days after the surgery. Compared with the normal group and the sham operation group, left ventricle index in the operation group got higher, left ventricle posterior wall index and interventricular septum index got lower, fraction shortening and ejection fraction got lower(P<0.05). There was no difference in the left atrium index (P>0.05). The BNP level was significantly increased (P<0.05), which was inversely related to ejection fraction and fraction shortening (r=-0.927,r=-0.894,P<0.05, respectively). The BNP level also had a positive relationship with the left ventricle index(r=0.409,P<0.05).

Ligature of the anterior descending branch of the left coronary artery in rats can successfully create heart failure model. Echocardiography can well evaluate the heart function in heart failure rat models.