Structural and Functional Features of the Cardiovascular System in Arterial Hypertension with Normal Spectrum of Transmitral Blood Flow

Objective: to assess the structural and functional features of the cardiovascular system in patients with arterial hypertension (AH) and normal spectrum of transmitral blood flow (NSTBF). Material and methods. An open prospective study of patients with essential hypertension (n=31) and healthy volunteers (n = 10) was organized at the state institution «Republican Research Center for Radiation Medicine and Human Ecology». The examined individuals were comparable in terms of sex and age features. All the participants of the study underwent transthoracic echocardiography (EchoCG) with the determination of the standard parameters, ultrasound of the extracranial part of the brachiocephalic arteries (BCA) with the determination of the thickness of the intima-media complex (CIM) and carotid plaques, duplex scanning of the arteries of the upper and lower extremities with the measurement of the ankle-brachial index (LPI) and endothelium-dependent vasodilation (EDVD). In addition, we assessed the global longitudinal deformation by the method of two-dimensional speckle tracking of the gray spots of the ultrasound image, the indicators of the movement of the fibrous ring of the atrioventricular valves into systole and diastole with the determination of the myocardial index by tissue dopplerography (TDG). Results. In comparison with the healthy volunteers, the patients with AH and NSTB have detected reliable changes in the anteroposterior size (38 mm versus 32.5 mm; p = 0.001) and volume (45 ml versus 31.5 ml; p = 0.002) of the left atrium (LP) and volume (37.5 ml versus 29.5 ml, p = 0.005) of the right atrium (PP), measured by means of standard transthoracic echocardiography. Using the method of two-dimensional tracking of the speckle spots of the gray scale of the ultrasound image we have recorded lower values of the global longitudinal strain (-17.5 versus -21.6; p < 0.001) in the study group compared with the control group, which indicates a violation of the biomechanics of the myocardial contractions of the left ventricle (LV). The study of the movement of the fibrous rings of the atrioventricular valves using tissue dopplerography (TDG) has showed that in the second group of the patients there are regional disorders of diastolic function, primarily this concerns the medial part of FC MK (1.3 versus 1.1; p = 0.05) and the lateral part of FC TC (1.3 versus 0.8; p = 0.028). In addition, in comparison with the healthy individuals we recorded higher values of the myocardial index for the lateral (0.51 versus 0.43; p = 0.001) and medial parts (0.59 versus 0.44; p = 0.001) FC MK, lateral part (0.58 versus 0.44; p = 0.001) FC TC. The patients of the study group, in comparison with the control one, have revealed signs of the pathological remodeling of the vascular wall. In the first group of the examined individuals, in comparison with the second one, the thickness of the intima-media complex (CIM) was slightly higher (p = 0.061 on the right, p = 0.08 on the left) and cases of the presence of atherosclerotic plaques (ASB) were recorded. Conclusion. The protocol research methods do not allow the comprehensive evaluation of the functional features of the heart in patients with AH, which requires additional diagnostic methods: TDH and speckle tracking.