Hypertrophic cardiomyopathy is a common genetically determined disease with unfavorable progno- sis. There is no common opinion about the mechanisms of its development. The purpose of the research is to study the features of longitudinal displacement of left ventricular walls in pa- tients with various forms of hypertrophic cardiomyopathy. Object and Methods. 93 patients with hypertrophic cardiomyopathy and 35 patients without cardiac pathol- ogy have been involved into study. Common laboratory methods of examination and complex echocardiography, including the Velocity Vector Imaging Echocardiography, have been carried out. Patients with hypertrophic cardio- myopathy have been assigned to 4 groups, depending on functional class according to NYHA and systolic gradient of the left ventricular outflow tract. Results and Discussion. The study showed that the more obstruction of outflow tract of the left ventricular is, the more intensified are the signs of heart failure in patients with hypertrophic cardiomyopathy. Patients with systolic gradient lower 30 mmHg (n = 35) have been assigned the Functional Class I according to NYHA (Group I). 28 pa- tients with systolic gradient greater 30 mmHg have been assigned the Functional Class II (Group II-А). The obstruc- tion rate greater than 30 mmHg has been observed in 13 patients, but the signs of heart failure were referred to the Functional Class III (Group II-B). Manifested signs of cardiac decompensation, referred to Functional Class IV, were observed in 17 patients (Group III) with systolic gradient lower 30 mmHg. The amplitude of longitudinal displacement of the left ventricular (LV) myocardium in normal condition and in hypertrophic cardiomyopathy in all walls was always peak at the level of basal segments and, gradually lowering, it was minimal at the apex. In the Group I only values of longitudinal displacement of basal segments of the inferior- (11,4 ± 4,2 mm), anterior-septal LV area (10,7 ± 3,1 mm) and anterior wall (13,5 ± 3,0 mm) were significantly below normal. Displacement of all LV segments was almost normal in the rest parts of the heart. Similar changes were observed in Group II-A. In patients from Group II-B, apart from changes, detected in Groups I and II-А, a significant lowering of displacement of basal parts of lateral (12,6 ± 3,2 mm), posterior (12,6 ± 3,4 mm) and inferior (11,2 ± 3,0 mm) walls has been observed. In Group III lowering of rates of longitudinal displacement of myocardium of septal and anterior areas of left ventricular is referred not only to the basal parts, but to the middle ones, too. There is also a significant decrease of displacement of segments of lateral, posterior and inferior walls. This process covers not only the basal and middle parts but even apical ones. Conclusions. In hypertrophic cardiomyopathy the vector of longitudinal systolic displacement of LV walls is similar to normal ones. During the systole the maximum values of longitudinal displacement are detected in LV basal parts both in normal condition and in hypertrophic cardiomyopathy. At the same time the apex of heart remains almost static. In hypertrophic cardiomyopathy the clinical signs depend on the value of systolic gradient in the left ventricular outflow tract. In hypertrophic cardiomyopathy there is a direct relation between the value of systolic gradient in the left ventricular outflow tract and number of segments with diminished function of longitudinal displacement, as well as the grade of circulatory deficiency. In hypertrophic cardiomyopathy rates of longitudinal displacement are lowering first in basal parts of anterior and septal areas. As the obstruction of left ventricular outflow tract increases, the rest segments are being involved into pathological process.
hypertrophic cardiomyopathy, echocardiography, longitudinal displacement, heart failure
«Bulletin of problems biology and medicine» Issue 4 part 1 (113), 2014 year, 208-212 pages, index UDK 616. 124-008. 46-072. 71
