Dobutamine-stress echocardiography speckle-tracking imaging in the assessment of hemodynamic significance of coronary artery stenosis in patients with moderate and high probability of coronary artery disease.

BACKGROUND AND OBJECTIVE: Myocardial deformation indices are considered as sensitive markers of ischemia and may be useful in the quantification of hemodynamic significance of coronary artery disease (CAD). We sought to determine the diagnostic value of speckle-tracking echocardiography derived myocardial deformation parameters at rest and during stress to determine hemodynamically significance coronary artery stenosis in patients with moderate and high probability of CAD. MATERIALS AND METHODS: In 81 patients (mean age, 64±8.6 years) with stable CAD inducible myocardial ischemia was evaluated by dobutamine stress echocardiography (DSE) and adenosine magnetic resonance imaging (AMRI). Based on AMRI patients were divided into two groups: nonpathologic (n=41) and pathologic (n=40). Strain and strain rate (SR) parameters and their changes from the rest (BASE) to low stress (MIN), peak stress (MAX), and recovery (REC) were analyzed using 2D speckle-tracking imaging (STI). RESULTS: In the nonpathologic group, systolic longitudinal and circumferential strain increased significantly from BASE to MIN, as well as systolic SR from BASE to MIN and from MIN to MAX in longitudinal plane. In contrast, in the pathologic group, insignificant longitudinal systolic SR increase and radial and circumferential systolic SR decrease from MIN to MAX was observed. Discriminant function analysis revealed that select STI derived parameters best classify patients into predefined AMRI groups (pathologic and nonpathologic) with the accuracy respectively 90.9% and 83.3%. According to ROC analysis these myocardial deformation parameters had the greatest predictive value of significant coronary artery stenoses: longitudinal strain at high dose (AUC 0.811, sensitivity 89.4%, specificity 64.7%), longitudinal strain rate at high dose (AUC 0.855, sensitivity 88.1%, specificity 71.0% at high doses). The sensitivity and specificity of inducible wall motion abnormalities were 74.0% and 85.0% (AUC 0.798) and was lower compared with the diagnostic value of longitudinal myocardial deformation parameters. CONCLUSIONS: Left ventricular strain and strain rate analyses during DSE can be used in the assessment of hemodynamic significance of coronary artery stenosis in patients with moderate and high risk for CAD.

Monitoring changes in heart tissue temperature and evaluation of graft function after coronary artery bypass grafting surgery.

Thermography is a relatively new contact-free method used in experimental and clinical studies and in cardiovascular surgery to investigate the myocardium and coronary artery function. Objects of complex study included mongrel dogs and patients with coronary artery disease who underwent cardiac surgery. For active dynamic thermography, we used a thermovision camera "A20V" (FLIR Systems, USA). Our data indicate that both experimental and clinical study performed on beating hearts could be an important approach to interoperation inspection of autovenous graft function. An infrared camera also can be successfully used to determine the extent of ischemic damage to the myocardium, heart, and blood vessels during surgery as a significant prognostic tool for evaluating outcome after cardiac operation.