Arterial hypertension: a path from unchanged transmitral bloodstream to dysfunction

Abstract

Objective: assess the parameters characterizing the structural and functional features of the cardiovascular system in patients with arterial hypertension (AH) with signs of diastolic dysfunction of the left ventricle (DDLV), to determine the dynamics of changes in the heart and vessels from the unchanged spectrum of transmitral bloodstream (USTB) to diastolic dysfunction (DD) in AH patients. Material and methods. An open prospective study of patients with essential AH and USTB (n = 34) and with DDLV signs (n = 45) was organized in the state institution «Republican Research Center for Radiation Medicine and Human Ecology». The examined individuals are comparable in terms of sex and age features. Standard transtoracal echocardiography with the determination of standard indices, ultrasonic examination of the extranial department of the brachyocephalic arteries (BCA) with the determination of the thickness of the intima-media complex (CIM), duplex scanning of the arteries of the upper and lower limbs with the determination of the ankle-shoulder index and endothelium-dependent were performed in all the participants of the study. In addition, global longitudinal deformation was evaluated by two-dimensional tracking of the grey spots of the ultrasonic image scale (speckle tracking), parameters of the movement of the fibrous ring of the mitral valve into systole and diastole with the determination of the myocardial index by the method of tissue dopplerography. Results. The examination of the heart by the method of standard transtoracal echocardiography has revealed that AH patients with DDLV (2nd group) in comparison with AH patients with the unchanged spectrum of transmitral bloodstream (1st group) detected higher values of interventricular partition (12 mm versus 9 mm, р = 0.001), relative wall thickness (0.41 versus 0.35, р = 0.033), the index of myocardial mass (65 g versus 58.5 g, р = 0.015). The isovolumetric relaxation time of the PG (81 ms versus 67 ms, p = 0.043), the rate of tricuspidal regurgitation and systolic pressure in the pulmonary artery were significantly higher in the group of AH patients with DDLV (p = 0.005). The analysis of the movement of the fibrous ring of the mitral valve by tissue dopplerography has showed that in the second group of the patients (AH with DDLV), there are signs of regional systolic dysfunction of the medial part of the fibrous ring of the mitral valve (0.08 cm/s versus 0.09, p = 0.047). E/Em was higher in the second group, a statistically significant difference was found for the lateral portion of the fibrous ring of the mitral valve (5.7 vs. 7, p = 0.019). The ultrasonic duplex scanning of the extranial part of the BCA revealed that in the AH patients with DDLV compared to the AH patients with the unchanged spectrum of transmitral bloodstream, the value of the thickness of the CIM is reliably higher (right 0.8 mm versus 0.65 mm, p = 0.001, left 0.8 mm versus 0.7 mm, p = 0.001). The study of the endothelium function has revealed that the second group of the patients compared to the first one, recorded reliably lower values of endothelium dependent vasodilation (10 % versus 14 %, p = 0.009). The analysis of subclinical lesion of the arteries of the lower limbs has revealed that in the group of patients with DDLV compared to the group of the AH patients with the unchanged spectrum of transmitral bloodstream, the ankle-shoulder index value is reliably higher (right 1.1 versus 1.07, p = 0.013, left 1.1 versus 1.07, p = 0.05). Conclusion. The protocol method of research - standard transthoracic echocardiography - does not allow to estimate fully the functional changes of cardiac muscle in AH patients with DDLV in comparison with AH patients with the unchanged spectrum of transmitral bloodstream. The application of additional diagnostic techniques (TDG and speckle tracking) makes it possible to get missing data. Pathologic transformation of transmitral bloodstream occurs when signs of systolic and diastolic dysfunction of the left ventricle already exist. The appearance of signs of diastolic dysfunction of the left ventricle during standard echocardiography is accompanied by pathologic remodeling of the vascular system.