OBJECTIVE: To evaluate the diastolic left ventricular function by echocardiography one and three weeks after acute myocardial infarction (AMI). METHOD: Nineteen Wistar rats (mean 209 g) were utilized. After anesthesia with ketamine (50mg/kg) and xylazine (10mg/kg), the left coronary artery was ligated after left thoracotomy to cause myocardial infarction. The animals were divided in two groups: group A (control, n=7) and group B (n=9). Echocardiographic evaluation was undertaken in the control group and one week (B1, n=9) and three weeks (B3, n=8) post-AMI in group B animals. The cardiac function was evaluated using a 21275 A HP Sonos 1500 Echocardiography equipped with 7.5/5.5 MHz transducer. Diastolic function was evaluated by transmitral flow, by analysis of the A wave, E wave and atrial left volume (LAV). Histological specimens were evaluated on third week. RESULTS: There were no differences on E wave analyses (A=62cm/s, B1=65cm/s, B3=69cm/s) or A wave analyses (A=43cm/s, B1=40cm/s, B3=41cm/s) between the groups. There was an increase in LAV; A vs B1 and A vs B3 (A=0.05mL vs B1=0.15mL, p=0.04 e A vs B3=0.14mL, p=0.01). Histological examination confirmed AMI in all animals. CONCLUSIONS: The LAV may be useful to assess the diastolic function in rats with AMI. LAV could reflect increases in left ventricular end-diastolic pressure secondary to systolic or diastolic dysfunction.
Myocardial infarction; Myocardial contraction; Echocardiography
