Sukhova S. Functional state of the right ventricle myocardium according to the speckle tracking echocardiography in diagnostics and for evaluation the effectiveness of pulmonary embolism treatment

The aim of the thesis was to improve the effectiveness of treatment of patients with acute pulmonary embolism (PE) by improving the right ventricular dysfunction (RVD) diagnostics based on the study of pathogenic and prognostic value of the right ventricular (RV) contractile function indicators using speckle-tracking echocardiography (2D STE). Relevance of the work is determined by an increase in the incidence of pulmonary embolism, severe clinical course and high mortality. 104 patients with acute pulmonary embolism, average age of 62.9 ± 13.5 years, were examined. Dynamics of clinical and instrumental indices was monitored for 4.2 ± 0.9 months during anticoagulant therapy (ACT). The control group involved 15 people without pulmonary hypertension of any etiology comparable by main indicators. Contractile dysfunction of RV myocardium in patients with acute PE was determined with help of 2D STE. The most sensitive and specific indicators for assessing RVD in patients with acute PE were the segmental ejection fraction (SEF) of the right ventricular apical segment (RVAS) and the degree of global longitudinal deformation of the RV free wall (longitudinal strain). Decrease of segmental contractility was proved even in patients with acute PE without signs of RVD according to transthoracic echocardiogram (TTE). After 4.2 ± 0.9 months of treatment, warfarin and rivaroxaban were equally effective in reducing the mean pulmonary arterial pressure (PAP) and reducing dimensions of the right cavities of the heart according to TTE. At the same time, according to the results of 2D STE it was found that RV contractile reserve was clearly improved during using rivaroxaban, especially in the presence of type 2 diabetes mellitus or a decrease in the velocity of glomerular filtration for less than 60 ml / min / 1.73 m2 and with a delay of the start of the ACT more than 9 days. In patients with acute PE, the growth of hospital mortality was associated with the presence of obesity, arterial hypotension, increased levels of creatinine, increased respiratory frequency and female sex. The risk of recurrent VTE was increased in the presence of factors such as thoracic localization of thrombosis according to venous duplex ultrasound (VDUS), AF, varicose veins (VV) or recurrence of PE in the anamnesis and index of SEF RVAS up to 65%. The risk of bleeding in patients with acute PE was associated with the presence of arterial hypertension (AH), and the use of drugs such as streptokinase and warfarin. The scientific novelty is that for the first time it has been defined that the most informative indicators of 2D STE for the determining RVD in patients with acute PE are the RV longitudinal strain rate and SEF RVAS. For the first time these indicators were used to assess the effectiveness of ACT and the optimal scheme of PE treatment was defined, what will provide the most significant effect on the restoration of functional state of RV myocardium and decrease in pulmonary hypertension. The value of research results is in the usage 2D STE indexes such as RV longitudinal strain and SEF RVAS what helps to stratify patients with moderate risk of early death from PE more accurately and individualize approaches to therapy. The necessity of ACT with the usage of rivaroxaban's direct inhibitor of activated factor X with the presence of type 2 DM, reduction of GFR less than 60 ml / min / 1.73 m2 and the delayed onset of ACT for more than 9 days, was substantiated.