Evaluation of ATP-PostC protective effect on myocardial function: A speckle tracking echocardiography study in ischemia-reperfusion injury

Abstract Background: Ischemia-reperfusion injury (IRI) seriously affects the prognosis of patients. We sought to use speckle tracking echocardiography (STE) to accurately evaluate the effect of drugs. Methods: In this study, STE was used to quantitatively evaluate the changes of myocardial function before and after reperfusion in myocardial ischemia rabbits with ischemia postconditioning (I-PostC) or ATP postconditioning. The variations of the left ventricular (LV) longitudinal, circumferential and radial myocardium were detected by STE technique. Meanwhile, a series of biochemical experiments were performed including myocardial enzymes assay, myocardial infarction size assay and TUNEL assay. Results: After ligation of coronary artery for 45 min, the strain and strain rate curves of left ventricular myocardium was disordered. The most STE parameters were significantly diminished and the time of reaching peak was delayed. After reperfusion for 120 min, the parameters (longitudinal, circumferential, radial strain and strain rate, as well as ventricular torsion function) were obvious recovery in I-PostC and ATP postconditioning groups. The sensitivity and specificity of global circumferential peak strain (GCSp), global longitudinal peak strain (GLSp), peak twist (Ptw) and peak twisting velocity (PTV) to diagnose myocardial infarction rabbits were 86.1% and 75%, 79.2% and 72.5%, 79.2% and 75%, 66.7% and 70.8%, respectively. The levels of aspartate aminotransferase (AST) and creatine phosphokinase isozyme (CKMB) were up-regulated in I/R group. AST and lactate dehydrogenase (LDH) values significantly reduced in the other three groups. The Bax expression was decreased, simultaneously, the Bcl-2 expression was increased after I-PostC and ATP postconditioning treatment. Conclusions: The application of STE in the assessment of IRI has high accuracy and reproducibility. Therefore, ATP has an important clinical value as a pharmacologic postconditioning drug.