Dynamics of Right Ventricle Pressure During Stress Echocardiography in Patients with Heart Failure with Preserved Ejection Fraction

Shortness of breath during physical exertion is a non-specific symptom that can hide such potentially dangerous diseases as structural or functional bronchopulmonary, coronary heart disease, structural cardiac disease, but the frequent cause is left ventricle diastolic dysfunction due to its significant hypertrophy. Pathogenetic mechanisms leading to this symptom require detailed study for the possibility of a comprehensive approach in the treatment of such patients with the aim of maximally improving their prognosis and quality of life. Objective — evaluate changes in right ventricle systolic pressure during stress echocardiography in patients with LV myocardial hypertrophy and clinical manifestations of heart failure, search for other mechanisms leading to clinical symptoms. Materials and methods. The study included 49 patients with shortness of breath during physical exertion, who underwent further diagnostic examination after exclusion of coronary stenotic lesions by invasive coronary and ventricular angiography. Patients were excluded from bronchopulmonary pathology using spirometry and chest radiography, structural heart pathology using echocardiography, microvascular angina using echocardiography with intravenous dipyridamole infusion, and the change in systolic pressure in the right ventricle was investigated using echocardiography during a physical exercise test. Results and discussion. There were no cases of infiltrative lung changes, signs of emphysema, or other manifestations of significant pathology according to X-ray data. Spirometry also showed the absence of significant functional abnormalities. Echocardiography revealed significant hypertrophy of LV myocar­dium (thickness of IVS — on average (14.1 ± 0.5) mm, posterior wall thickness — on average (13.5 ± 0.3) mm) with the presence of LV diastolic dysfunction and echocardiographic signs of increased end-diastolic pressure in the LV, which was confirmed invasively during coronary and ventricular angiography. In 9 (18.4 %) cases, heart wall thickening was due to hypertrophic cardiomyopathy according to cardiac MRI, these patients had LV outflow tract obstruction and mild pulmonary hypertension at rest. Conducting strain imaging showed the presence of signs of myocardial ischemia (segmental contractility disorder) with varying degrees of severity (from 1 to 5 segments), which spread to the IVS, the apex of the heart and, less often, to the anterior wall of the LV. All patients experienced an increase in pulmonary artery systolic pressure during exercise, on average, from (37.4 ± 2.1) to (47.1 ± 1.6) mm Hg. Conclusions. The pathogenic mechanism underlying shortness of breath in patients with LV myocardial hypertrophy involves transient pulmonary hypertension occurring during exercise due to left ventricular diastolic dysfunction. Another contributing factor is the development of myocardial ischemia during physical exertion, which, in the absence of coronary stenosis and microvascular angina, is attributed to inadequate supply of coronary blood flow volume velocity relative to the significant left ventricular hypertrophy.