Evaluation of the use of the myocardial performance index as a parameter of cardiac function in two experimental models of heart disease: myocardial infarction and pulmonary hypertension.

Myocardial performance index (MPI) has been used in the estimation of ventricular function in a non-invasive way through echocardiography. This index has presented relevant results in clinical and experimental studies. However, there are no studies evaluating whether this index correlates with other cardiac parameters in experimental models of heart disease, such as monocrotaline-induced pulmonary artery hypertension (PAH) and acute myocardial infarction (AMI). In view of that, the present study evaluated rats submitted to PAH and perform a broad analysis of echocardiographic, hemodynamic and morphometric parameters of the right ventricle (RV) and pulmonary artery (PA). Besides that, the present study also evaluated rats submitted to experimental AMI and performed a broad echocardiographic evaluation of left ventricle (LV). Subsequently, it was analyzed whether the parameters collected presented correlation with the MPI. In PAH model, monocrotaline was administrated and the animals were divided into the following groups: control and PAH. In AMI model, infarction was induced by coronary artery ligation and the groups were as follows: SHAM and AMI. In PAH model, MPI presented correlation with RV functional parameters, as well as with parameters that evaluate flow and resistance in the PA. In addition, this index also presented correlation with LV parameters in infarcted rats. To our knowledge, this is the first study that evaluates the correlation of MPI with parameters of the RV in rats with PAH induce by monocrotaline. Besides that, this is the first study that compares the use of this index in two different experimental models of cardiac diseases.