Purpose — to study peculiarities of three-dimensional organization of the heart ventricular myocardium.

Materials and methods. The work is based on the results of the macroscopic study of pig hearts, which were prepared by methods of: F. Torrent-Guasp (n = 10), A. S. Gulyayeva, I. M. Roshevskaya (n = 5) and our modification of A. S. Gulyayeva method (n = 5). In connection with the general principle of the structure of myocardium in all mammals, macroscopic research results were extrapolated to human beings. The serial sections of the ventricles of 12 fetal hearts of 22 week gestation and 3 adult hearts (sectional material) were used to study the histological structure of the human myocardium.

Results and discussion. Certain branches deviate from the side surfaces of cardiomyocytes to one side, giving rise to new myocardial bundles, directed at an angle to the initial bundles. This process leads to build-up of myocardial mass from the apex to the base of the heart and at the same time — to forming muscle bundles of different directions. The cardiomyocytes of the inner ventricular myocardial layer are directed from the apex to the base of the heart in an oblique direction counterclockwise. The cardiomyocytes of the outer layer are connected at an angle to cardiomyocytes of the inner layer and form stratum which is directed from the base of the heart to its apex clockwise. At the level of left ventricular papillary muscles, the majority of cardiomyocytes of inner and outer layers change their direction, creating a middle circular layer of the myocardium. There is a vertical muscle bundle in the area of posterior interventricular sulcus, giving branches to the interventricular septum, and to the basal parts of both ventricles and right ventricular crista supraventricularis. This bundle in the state of contraction may serve as the fulcrum for myocardium of the basal of the heart. In addition, contracted trabecules, which are oriented along the longitudinal axis of the heart, serve as fulcrum for left ventricle myocardium. The muscle fibers of the inner layer of the left ventricle intertwine at an angle to these trabeculеs by separated groups, which provides rotary component to the movement of left ventricle. Right ventricular trabecules connect opposite walls of this heart chamber, reinforcing the constricting function of right ventricle walls. There are two longitudinal muscle bundles in the anterior wall of the left ventricular outflow tract. They go from aorta ostium to the basal ends of the aorta and to the interventricular septum; during systole they have to pull up the aortic root toward the blood flow ejected from the left ventricle.

Conclusions. Myocardium is a closed, three-dimensional syntcytium-like structure with multidirectional bundles of muscle fibers whose consolidative, consecutive (from apex to base) contraction provides the most effective constrictive-rotary mode of left ventricle.

Keywords: heart, myocardium, morphology.

Purpose — to estimate the prevalence of increasing the pressure of the left ventricle (LV) and to identify predictors of increasing the E/e 'according to the stress echocardiography with exercise stress and definition of left ventricular (LV) diastolic function by tissue Doppler imaging in men with isolated arterial hypertension (AH) of stage of I — III degree.

Materials and methods. The study included 275 hypertensive males who underwent treadmill diastolic stress echocardiography. All patients underwent a standard clinical and laboratory examination, had ambulatory blood pressure monitoring and transthoracic echocardiography with tissue Doppler. Calculation of Е/е' was performed at rest and immediately after termination of submaximal treadmill test. Postexercise Е/е' > 13 was considered to be pathological. Logistic regression analysis was used to find predictors of postexercise Е/е'.

Results and discussion. Elevation of E/e' > 13 immediately after treadmill test was reported in 17 (6.6 %) patients. The factors affecting postexercise E/e', according to the results of logistic regression analysis, were age, left ventricle mass index (LVMI), linear diastolic dimension of left atrium (LA), resting LV diastolic dysfunction, glucose, creatinine, and C-reactive protein levels, exercise tolerance and the resting E/e'. LVMI > 138 g/m2 and resting E/e' > 8 were independent predictors according to multivariate analysis. Independent predictors were LVMI > 138 g/m² (OR 1.48; 95 % CI 1.06 — 2.08; p = 0.02) and resting Е/е' > 8 (OR 1.02; 95 % CI 1.003 — 1.04; p = 0.02) according to multivariable analysis.

Conclusions. The prevalence of pathological postexercise Е/е' elevation was 6.6 % in men with uncomplicated AH. LVMI and resting Е/е' were independent predictors of LV filling pressure elevation. The stress echocardiography with postexercise Е/е' evaluation can be recommended for patients with moderate to severe LV hypertrophy and resting Е/е' > 8 to identify patients at risk of heart failure with preserved LV ejection fraction.

Keywords: arterial hypertension, left ventricle filling pressure, stress echocardiography, exercise.

Purpose — to investigate the indices of homocysteine (HC) metabolism levels in patients with chronic coronary heart disease (CHD) with different levels of risk of cardiovascular complications in comparison with healthy subjects.

Materials and methods. Evaluation of homocysteine level in the blood plasma was conducted in 51 patients (40 (78.4 %) men and 11(21.6 %) women) of average age of (46.9 ± 4.5) years, with a diagnosis of CHD and stable exertional angina of I — IV functional class with the use of reagent kit of the company «Axis-Shield» (UK) and the enzyme immunoassay analyzer «Stat Fax 2100» (USA). The cysteine level in plasma was determined by the modified Gaytonde method, the methionine level in plasma was determined by the Sullivan method. The risk of development of cardiovascular complications in patients with CHD was evaluated in accordance with the recommendations of the European Society of Cardiology (2013). The results were compared with those of 53 healthy subjects of the same age and gender.

Results and discussion. The low-risk group included 25 (49 %) patients with CHD, the high-risk group included 26 (51 %) patents. The average homocysteine level in patients with CHD was significantly higher than in healthy subjects (9.75 ± 2.04 vs. 8.26+1.13) μmol/l, respectively, р < 0.05). The average methionine levels did not differ in CHD patients with low and high risk (19.94 ± 3.84 vs. 20.55 ± 4.07) μmol/l, respectively; t = 0.69, p > 0.05), but in both groups it was significantly higher than in the control group (17.44+2.59) μmol/l, p < 0.05). The group of CHD patients with a high risk of cardiovascular complications showed significant correlation between homocysteine and cysteine levels on the one hand, and between the methionine and cysteine, on the other hand (r₂ = 0.52, t₂ = 0.008, p < 0.01 and r₂ = –0.49, t₂ = 0.014, p < 0.05, respectively), in contrast with a low-risk group of patients with CHD (t₁ = 0.61, t₂ = 0.53 at t5 % < 0.05).

Conclusions. Hyperhomocisteinemia was detected in 19.2 % of CHD patients with a high risk of development of cardiovascular complications, meanwhile it was absent in healthy subjects of the same age and gender. A direct linear correlation of average strength between the concentrations of homocysteine and cysteine, and an inverse linear correlation between the concentrations of methionine and cysteine were detected in CHD patients with a high risk of development of cardiovascular complications in contrast with healthy subjects of the same age and gender.

Keywords: coronary heart disease, risk factors, homocysteine, methionine, hyperhomocysteinemia, cysteine.

Purpose — to diagnose noncoronary degenerative process in the myocardium of airline workers who experience long-term combined effects of local pulse vibration and on-the-job noise.

Materials and methods. 130 people with cardialgia syndrome were examined at the clinics of occupational diseases of O. O. Bogomolets National Medical University and M. M. Amosov National Institute of Cardiovascular Surgery of NAMS of Ukraine in the period from 2010 to 2013 using coronaroventriculography (CVG) method. The main group (87 people) consisted of airline workers that in the process of work experience long-term combined effects of local pulse vibration and on-the-job noise. The control group included 43 patients, age and gender matched with the main group, who were not exposed to these factors. Besides CVG, all patients underwent intensive cardiac and general clinical examination.

Results and discussion. In the main group, features of hemodynamically significant atherosclerotic process was found in 24.1 %; in the control group, the number of such patients was 23.6 %. The average value of stenosis according to CVG in the main group was (41.8 ± 6.7) %, in the control group — (44.4 ± 7.2) %. The right type of coronary circulation (CC) prevailed in both groups (60.9 and 55.8 %, respectively). Left type of CC was detected in 23.0 % patients of the main group and in 32.6 % of the control group. Balanced CC type was most rarely recorded: in 16.1 % patients of the main and in 14.0 % patients of the control group. The effect of basic modification factors of cardiovascular risk in the development of atherosclerotic process in coronary arteries did not reveal statistically significant differences between groups of comparison. The persons without CVG-signs of coronary vessels lesion surveyed by the method of vectorechocardiography showed the prevalence of degenerative process in the cardiac muscle of workers of vibro-noise professions.

Conclusions. No significant differences in frequency and degree of development of atherosclerotic process in the wall of coronary arteries were found in the surveyed individuals and the control group. The reason of cardialgia syndrome in patients of the main group can be noncoronary dystrophic process that develops in the myocardium of workers due to the combined effects of long-term local vibration and on-the-job noise.

Keywords: vibration, noise, dystrophic process, coronaroventriculography, vectorechocardiography, longitudinal deformation of left ventricular myocardium.

Purpose — to determine the effectiveness of a unified stepwise simplified algorithm of antihypertensive therapy (AT) for reaching the target office and normal home (≤ 135/85 mmHg) blood pressure (BP) in patients with arterial hypertension of grade 3 compared to patients with AH of grades 1 — 2 and improving their adherence to treatment in general outpatient practice of a cardiologist.

Materials and methods. 54 outpatient cardiologists of Kiev medical institutions took part in PERFECT open prospective study which included 431 patients aged 35 to 70 years (mean age (57.3 ± 0.5) years) with uncomplicated essential hypertension. Blood pressure of patients who were treated before was > 160/100 mmHg blood pressure of those who were not treated was ≥ 140/90 mmHg 6 main and 2 additional visits as needed were carried out within 6 months. During the first visit, the doctor determined the blood pressure using a standardized automatic device Microlife BPW200 with a universal cuff. The patient was provided with automatic oscillometric device Microlife BP3AG1, trained to use it, instructed as to lifestyle modifications and prescribed a fixed combination of perindopril and amlodipine at a dose of 5/5, 5/10, 10/5 or 10/10 mg at the doctor’s option (step 1). Before each subsequent visit, the patients measured their blood pressure on their own twice a day for 7 days and recorded the results in a diary. In case of failure to reach the target office BP (< 140/90 mmHg), on subsequent visits, the dose of fixed combination of perindopril and amlodipinewas increased to the maximum tolerated (step 2) and the doctor consistently administered indapamide-retard 1.5 mg/day (step 3), spironolactone 25 mg twice a day (step 4), moxonidine 0.2 to 0.6 mg/day or doxazosin 4 — 8 mg/day (step 5). The adherence to treatment through a questionnaire (X. Girerd et al., 2001) was evaluated during the first visit in patients who received antihypertensive therapy before the study and during the final visit in all patients. Efficacy of treatment was assessed by the primary endpoints: the number of patients who achieved the target level of office BP after 6 months of follow up, and the number of patients with a normal home blood pressure (< 135/85 mmHg) and by the secondary endpoints: change in adherence to treatment and incidence of side effects of antihypertensive therapy.

Results and discussion. On the first visit, according to the survey, 93 (21.6 %) patients with hypertension of grade 3 composed group 1, and 338 (78.4 %) patients with hypertension of grade 1 — 2 composed group 2. Patients in both groups were matched for age, body mass index, the frequency of detection of concomitant coronary heart disease, type 2 diabetes and target organ damage, as well as the number of smokers. Group 1 had more male patients (p < 0.05). In 6 months, mean systolic office blood pressure decreased from (184.1 ± 1.0) to (134.0 ± 1.1) mmHg and from (160.7 ± 0.5) to (130.1 ± 0.5) mmHg, mean diastolic office blood pressure — from (106.8 ± 0.9) to (80.5 ± 0.8) mmHg and from (94.6 ± 0.4) to (78.8 ± 0.4) mmHg, respectively, in patients of groups 1 and 2 (all p < 0.001). Target level of office BP was achieved in 69.9 % patients of group 1 and 86.4 % patients of group 2, the normal level of home blood pressure — in 48.4 and 67.2 %, respectively. A low level of adherence to treatment during the first visit was noted in 39 (46.4 %) and 142 (52 %), during the sixth visit — in 2 (2.4 %) and 23 (8.4 %) patients of groups 1 and 2, respectively, (all p < 0.01); a high level of adherence during the first visit — in 30 (35.7 %) and 62 (22.7 %), during the sixth visit — in 50 (59.5 %) and 128 (46.9 %) patients of groups 1 and 2, respectively (all p < 0.01).

Conclusions. In treatment of uncomplicated hypertension, the use of stepwise treatment algorithm based on a fixed combination of perindopril and amlodipine with control of home blood pressure and educational program in ambulatory practice of cardiologists allowed in 6 months of treatment to reach the target level of office blood pressure in 69.9 % patients with hypertension of grade 3 and in 86.4 % patients with hypertension of grade 1 and 2, which was accompanied by a decrease in home blood pressure to normal levels (≤ 135/85 mmHg) in 48.4 and 67.2 % cases, respectively. This approach proved to be effective regardless of baseline blood pressure, and according to X. Girerd questionnaire ensured a high and moderate adherence to treatment in 97.6 % patients with hypertension of grade 3 and in 91.6 % patients with hypertension of grade 1 and 2.

Keywords: essential arterial hypertension, target blood pressure, perindopril, amlodipine, fixed low-dose combination, adherence to treatment.

Purpose — to study the characteristics of structural and functional changes of the heart in patients with ischemic heart disease (IHD) who had previous myocardial infarction (MI) and type 2 diabetes mellitus (DM) compared with patients without diabetes.

Materials and methods. The study involved 87 patients (mean age — 60.21 ± 0.87 g), of which 31 — patients with IHD who had previous myocardial infarction and type 2 DM (main group), 29 patients with myocardial infarction (MI) without DM and 27 — patients with isolated type 2 DM. Echocardiography with the assessment of morphological and functional state of the myocardium was performed by the standard method.

Results and discussion. The main group, unlike the control group, showed a significant increase in the size of all heart cavities (p < 0.001) and left ventricular (LV) walls thickening (p < 0.001), lower ejection fraction (EF) (p < 0.001) and ventricular diastolic dysfunction (DD) with a predominance of relaxation type of DD, increase of pressure in the pulmonary artery (p < 0.001). The comparison of the echocardiographic parameters of patients of the main group to those of patients with IHD who had MI without type 2 DM showed a significant increase in the size of LA (p < 0.01) and RA (< 0.05), lower ejection fraction (p < 0.01), a deeper diastolic dysfunction of LV and RV. Indexes of the morpho-functional state of the myocardium in the main group compared to those in patients with isolated type 2 DM are characterized by significant increase in the size of the LA (p < 0.05), lower ejection fraction (p < 0.001) and a marked disturbance of LV diastole.

Conclusions. Type 2 DM patients with IHD who had previous MI compared with similar patients without DM in our study werea marked with an increased end-systolic size of LV and atriums size of the heart, left ventricular remodeling mainly by the concentric hypertrophy type, deeper diastolic dysfunction of the LV and RV and a significant left ventricular systolic dysfunction.

Keywords: ischemic heart disease, myocardial infarction, type 2 diabetes mellitus, echocardiography.

Purpose — to determine the parameters of laser doppler flowmetry (LDF) in patients with varying degrees of chronic lower limb ischemia (CLLI) by Fontaine and their correlation with clinical and ultrasonographic parameters of macrohemodynamics.

Materials and methods. In the period from 2010 to 2013, a prospective open-label study included 60 patients with CLLI. The average age of the patients was 68.0 ± 7.9 years (47 to 72 years). The mean duration of symptoms was 2 months (from 2 weeks to 1 year). 20 patients had CLLI of stage II by Fontaine (group B), 20 patients had stage III (C) and 20 patients had stage IV (D). LDF data of 15 healthy volunteers matched by age and comorbidity were used for control (group A). Systolic segmental pressure at the ankle and LDF with the use of occlusion test were evaluated.

Results and discussion. A statistically significant difference between all groups in systolic pressure at the ankle was identified. In group A, the ankle-brachial index (ABI) was 0.9 — 1.2, in Group B — 0.8 — 0.6, C — 0.5 — 0.4, D — 0.3 or less. The most significant changes are observed in the field of HF- and CF-oscillations. Thus, the contribution of HF-oscillations in the overall spectrum of oscillations in patients with CLLI is increased to 15 %, whereas it is normally about 5 %; in the field of cardio-rhythm, it grows up to 6 — 7 % (normal 1.1 — 1.3 %). Severity of changes in the amplitude of rhythmic components of flux motions is directly related to the stage of CLLI and degree of blood circulation abnormality. Our results show a close correlation between segmental systolic pressure, ABI and indicators of LDF, ie. indicators of macro and microhemodynamics.

Conclusions. Of great importance in the diagnosis and especially the control over the quality of treatment is the estimation of the degree of microcirculatory disorders, which is closely correlated with such indicators of macrodynamics as segmental pressure on the ankle arteries and ABI. Criteria of critical ischemia of the lower limb tissue can be as follows: a very low microcirculation indicator (less than 2 perf. un.); sharp decline in the level of flux motion (root-mean-square deviation of less than 0.2 perf. un.); sharp decrease or absence of vasomotor waves of LF-rate; increase of the amplitude of the HF-rate to 0.2 — 0.3 perf. units; increase of CF-amplitude rhythm to 0.3 — 0.4 perf. units.

Keywords: duplex laser flowmetry, chronic lower limb ischemia, diagnosis.

Purpose — to assess the effectiveness of L-arginine in chronic lower limb ischemia management in case of occlusive-stenotic involvement of great vessels with regard to atherosclerosis.

Materials and methods. According to Fonteyn — Pokrovsky, 62 patients were examined with atherosclerotic arterial lower limb involvement with IIB level of chronic ischemia. The age of each patient varied from 53 to 76 years, the average age — 58.0 ± 2.4. All patients had complex medical therapy in hospital for 10 days followed by ambulatory treatment in accordance with international recommendations (TASK-II, 2007). According to the therapy, patients were divided into 2 groups. The main group consisted of 30 patients, who in addition took 100.0 ml of 4.2 % arginine hydrochloride solution intravenously and 5 ml of arginine aspartate solution (1 measuring spoon — 1 g of drug) orally 3 times a day with food. The control group consisted of 32 patients who took none of those solutions.

Results and discussion. All patients noted a positive clinical effect after this treatment. Objective evaluation of results showed that after medical treatment and administration of 4.2 % arginine hydrochloride solution with arginine aspartate, all patients of both group increased their pain-free walking distance on an average by more than 100.0 m (p < 0.001). The use of such solutions also contributed to remarkable reduction in pain intensity. These results also demonstrate a tendency towards the increase of ABI level values in comparison with the control group. Due to atherosclerosis, it was noted the positive L-arginine impact on blood circulation state in distal chronic lower limbs ischemia.

Conclusions. Because of the atherosclerotic vascular disease, the positive clinical effect was caused by intravenous 4.2 % arginine hydrochloride with oral L-arginine aspartate solutions in complex medical treatment of chronic lower limbs ischemia of IIB level, which was expressed by the pain attenuation in gastronemius muscles during the walking and the increase of the pain-free walking distance from (182.5 ± 21.4) to (349.1 ± 19.1) meters. Such effect also encouraged the growth of local systolic pressure indicators and ankle-brachial indexes.

Keywords: atherosclerosis, lower limb ischemia, treatment, L-arginine, chronic ischemia.

The review discusses the potential role of various tissue-specific micro-RNAs as markers of cardiovascular remodeling and indicators of the progression of heart failure (HF). Differential expression of various micro-RNAs in the cardiomyocytes and on the surface of circulating mononuclear cells was detected in physiological conditions and severe HF in patients with cardiomyopathy. In addition, it was found that the level of circulating micro-RNAs may reflect the severity of diastolic and systolic myocardial dysfunction in patients with severe HF. Because each micro-RNA can be associated with a unidirectional array of processes, the potential for control of such signals is regarded as a promising prospect in respect of reversion of pathological cardiac remodeling. Many researchers believe that micro-RNAs can represent not only potential molecular targets for pharmacotherapy, but perhaps can be indicators of risk of adverse clinical outcomes in chronic HF. The authors present and discuss data that reveal the diagnostic and prognostic potential of various micro-RNAs in patients with myocardial dysfunction.

Keywords: micro-RNA, heart failure, cardiovascular remodeling, diagnostic and prognostic value.

A number of diseases and conditions are accompanied by the development of primary right ventricular heart failure (RVHF) without left ventricular failure. The review presents the current information on the pathogenesis and possibilities of correction of RVHF in chronic pulmonary heart disease, pulmonary embolism, diseases which are attributable to pulmonary hypertension, congenital heart defects. Groups of drugs that are used for medical treatment of RVHF, and especially their application in different patients are discussed. Much attention is paid to the review of the most common forms of RVHF developing in patients with diseases of the left heart which remain the least studied to date. Causes and mechanisms are discussed of pulmonary arterial hypertension and RVHF associated with systolic and diastolic left ventricular dysfunction, and diagnostic methods that allow objective differentiation of cases of passive and reactive excessive pulmonary arterial hypertension. The author emphasizes that due to the variety of forms of RVHF and according to modern views on the etiology and pathogenesis of their development, the classification of chronic heart failure by M. D. Strazhesko and V. H. Vasylenko cannot be applied when RVHF develops initially, without prior left ventricular heart failure, and the treatment of various diseases characterized by RVHF requires mandatory consideration of their features.

Keywords: heart failure, right ventricular heart failure, pulmonary hypertension, pulmonary arterial hypertension.

The article presents a literature review on one of the forms of haemangioendothelioma — epithelioid, rare vascular tumor, which is intermediate between haemangioma and angiosarcoma by its morphological features and biologic behavior. Scientific literature informs about cases of epithelioid haemangioendotheliomas in hepar, lung, gastrointestinal truct, head, neck, central nervous system, vessels, heart and bones. Tumor is a well-differentiated endothelial one with unpredictable behavior.

Keywords: haemangioendothelioma, epithelioid, vascular tumor, haemangioma, angiosarcoma.

Pathologic deformation of internal carotid artery (ICA) is common anomaly in children. It is a kind of congenital vascular malformation with hereditary predisposition. Pathologic ICA deformation can be a cause of cerebrovascular insufficiency in childhood. Cerebral ischemia develops because of local disorders of circulation in the artery which lead to deceleration of blood flow velocity in brain vessels. There are two approaches to its treatment — therapeutic and surgical.

Keywords: pathologic deformation of internal carotid artery, etiology, disorders of brain circulation, children, treatment.

Currently, transcatheter technique in cardiology has reached a high level of development. From an applied specialty, it turned into an independent branch of medicine, offering new effective low-impact methods of treatment. Almost every year there are new hightech methods and devices. This article describes the history of heart and vessels catheterization techniques in Ukraine at the turn of the XX—XXI centuries.

Keywords: catheterization of heart and blood vessels, balloon valvuloplasty, stenting of arteries, aortic endoprosthesis, transcatheter closure of defects of the heart walls.

Реестр перкутанных коронарных вмешательств (Реестр ПКВ) был создан в середине 2010 г. Всеукраинской общественной организацией «Ассоциация интервенционных кардиологов Украины». Первый протокол был заполнен 12.04.2010 г. К настоящему моменту (10.08.2014 г., 20 ч 00 мин) в Реестре ПКВ заполнено 40 177 протоколов пациентов (в августе 2012 г. эта цифра составила 25 252), которым проведена коронарография (КГ), ПКВ либо обе процедуры одновременно. За прошедший год увеличилось количество КГ и ПКВ на 19,3 и 26,3 % соответственно. Количество центров/отделений, в которых общее количество ПКВ составляет более 100 в год, увеличилось с 23 до 30 за период 2013 г. Анализ результатов реестра подтвердил увеличение количества первичных коронарных вмешательств у пациентов со STEMI за прошедший год на 45,6 %, уменьшилось поступление «поздних» (12 — 24 часа от начала симптомов) пациентов для первичного ПКВ с 23 до 19 %, что стало возможным за счет формирования Региональных реперфузионных сетей в восьми областях Украины. Впервые был проведен анализ количества выполненных первичных вмешательств на 1 млн населения в 23 областях Украины. Среднее количество первичных ПКВ на 1 млн населения — 75 (от 0 до 222). Одним из основных достижений в формировании Регионарных реперфузионных сетей в областях на базе реперфузионных центров, которые могут проводить первичные коронарные вмешательства у пациентов со STEMI в режиме 24/7, является снижение летальности не только в реперфузионных центрах, но и общей летальности пациентов с острым инфарктом миокарда в областях.

Keywords: коронарография, перкутанные коронарные вмешательства, реперфузионная терапия, острый инфаркт миокарда, ишемическая болезнь сердца.

Цель работы — изучить особенности трехмерной организации миокарда желудочков сердца.

Материалы и методы. Работа построена на результатах макроскопического изучения свиных сердец, препарированных по методу F. Torrent-Guasp (n = 10), А. С. Гуляевой и И. М. Рощевской (n = 5) и в нашей модификации метода А. С. Гуляевой (n = 5). В связи с общим принципом строения миокарда у млекопитающих результаты этих макроскопических исследований экстраполировали на человека. Для изучения гистологического строения миокарда человека использовали секционный материал (серийные срезы желудочков 12 сердец плодов 22-й недели гестации и 3 сердец взрослых людей).

Результаты и обсуждение. От боковых поверхностей определенных кардиомиоцитов (КМЦ) в одну сторону отходят ответвления, дающие начало новым миокардиальным пучкам, направленным под углом к исходным. За счет этого происходит наращивание массы миокарда от верхушки к основанию сердца и вместе с тем формируются разнонаправленные мышечные пучки. Во внутреннем слое миокарда левого желудочка (ЛЖ) КМЦ ориентированы от верхушки к основанию в косом направлении против часовой стрелки. Соединенные под углом с ними КМЦ наружного слоя формируют пласт, направленный от основания к верхушке по часовой стрелке. На уровне сосочковых мышц ЛЖ большинство КМЦ внутреннего и наружного слоев меняют свое направление, создавая средний циркулярный слой миокарда. В области задней межжелудочковой борозды существует вертикальный мышечный тяж, дающий ответвления в межжелудочковую перегородку, базальные отделы желудочков и наджелудочковый гребень правого желудочка (ПЖ). Этот тяж в состоянии сокращения может служить точкой опоры для миокарда основания желудочков. Точкой опоры для миокарда верхушечного отдела ЛЖ являются сокращающиеся трабекулы, которые ориентированы вдоль продольной оси сердца. В них под углом вплетаются разрозненными группами мышечные волокна внутреннего слоя желудочка, что сообщает ротационный компонент движению ЛЖ. Трабекулы ПЖ соединяют противоположные его стенки, усиливая констрикторную функцию миокарда ПЖ. В передней стенке выходного тракта ЛЖ от устья аорты к базальным концам трабекул и в межжелудочковой перегородке идут два продольных мышечных пучка, которые при сокращении должны подтягивать корень аорты навстречу потоку крови, изгоняемому из ЛЖ.

Выводы. Миокард представляет собою трехмерную замкнутую, синцитиоподобную структуру с разнонаправленными пучками мышечных волокон, консолидированное, последовательное (от верхушки к основанию) сокращение которых обеспечивает наиболее эффективный — констриктивно-ротационный — режим работы ЛЖ.

Keywords: сердце, миокард, морфология.