The rate of myocardial contraction in the assessment of diastolic function

Objective: to evaluate the results of biomechanics of myocardial contraction during diastole in patients with coronary heart disease based on the results of vector analysisMATERIAL: the study is based on 79 patients with coronary heart disease with myocardial infarction and scarring of the heart muscle aged 53±4 years and 34 healthy volunteers — 41±3 years were examined. Before and after the operation of coronary artery bypass grafting, transthoracic echocardiography was performed, followed by computer image processing and calculation of hemodynamic parameters — EDV, ESV, EF, E\A. Vector analysis was used to estimate the rate of myocardial displacement (V), from the apex to the basal region in six regions of the left ventricle.RESULTS. To determine the mechanical characteristics of left ventricular (LV) contraction, a method was used that allows dynamic series of ultrasound images to track the rate of myocardial contraction in the basal, middle and apical parts of the heart. Before surgery, during diastole, the rate of myocardial contraction increased by more than 30% in comparison with the norm in the basal, middle, and apical regions. Changes occur due to a decrease in myocardial perfusion. In response, hyperfunction occurs, which leads to the activity of additional cardiomyocytes in maintaining heart performance. After the operation, the recovery of myocardial contraction rates to normal values was noted.CONCLUSION. The results showed the dynamics of the rates of myocardial displacement mainly in the diastole, but there is no complete recovery in the hospital period. Diagnosis of the mechanical function of the myocardium during the cardiac cycle is based on the dynamics of the rates of contraction from the apex to the basal part of the left ventricle. Evaluation of the activity of myocardial contraction has certain advantages in determining the state of diastolic function of the left ventricle.

Segmental Myocardial Displacement and Tissue Velocity Analysis of the Right Ventricle in Hypoplastic Left Heart Syndrome Fetuses and Controls Using Color Tissue Doppler Imaging (C-TDI)

Introduction: The long-term outcome of patients with HLHS (hypoplastic left heart syndrome) is mainly determined by right ventricular function. Our study examines, whether there are differences in segmental right ventricular myocardial displacement and tissue velocities of fetuses with HLHS compared to healthy fetuses during gestation. Materials and methods: A prospective study was conducted including 20 fetuses with HLHS and 20 gestational age matched controls. c-TDI (colour tissue Doppler imaging) derived systolic and diastolic velocities as well as myocardial displacement were assessed in three different locations of the right ventricle (RV). A ROI (region of interest) was placed in the basal, middle and apical part of the myocardium. Possible changes of c-TDI indices in the course of pregnancy and between the three different segments were investigated in both groups. Results: HLHS fetuses showed significantly lower e' velocities measured in the basal and middle part of the RV compared to healthy controls (p < 0.05). Basal displacement showed significantly lower values in HLHS fetuses compared to controls. In control fetuses but not in HLHS fetuses there was a significant increase of basal diastolic velocities and displacement in the course of pregnancy. According to myocardial velocities and displacement values there was a significant decrease from the base of the fetal heart to the apex pointed in both groups. Conclusions: An altered right ventricular myocardial function in HLHS fetuses within different myocardial segments could be demonstrated. An apicobasal gradient with higher velocity and displacement values in the basal part of RV myocardium could be found in both groups. The technique may be of value in the prenatal assessment of myocardial function, however its role as a monitoring tool and outcome predictor needs to be defined.