Computational method to model flow through the mitral valve and early diastolic filling of the left ventricle

2002 ◽  
Author(s):  
A.C. Hunt
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Computational Method ◽  
Diastolic Filling ◽  
Model Flow ◽  
Flow Through

scholarly journals MORPHOFUNCTIONAL FEATURES OF THE MYOCARDIUM IN ITS DIASTOLIC OVERLOAD

2021 ◽  
Vol 17 (2) ◽  
pp. 39-46
Author(s):  
A.A. Balabai ◽  
A.A. Krikunov ◽  
P.M. Semeniv ◽  
E.V. Rudenko ◽  
V.P. Zakharova
Keyword(s):  
Heart Failure ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Blood Volume ◽  
Interstitial Fibrosis ◽  
Mitral Valve Insufficiency ◽  
Diastolic Filling ◽  
Myocardial Oxygen Demand ◽  
Statistical Research ◽  
Valve Insufficiency

Relevance. Adaptation of the heart chambers to their volume overload, which increases with diastolic filling of the left ventricle (LV) or systolic regurgitation in the left atrium (LA) in case of mitral valve insufficiency leads to remodeling of the myocardium of these chambers. Longitudinal hypertrophy of cardiomyocytes (CMCs), realized by building up new sarcomeres at the end of existing myofibrils, is an adaptation mechanism in the early stages, but eventually turns into maladjustment, which leads to heart failure. Hypertrophied CMCs, damaged during decompensation, are replaced by connective tissue due to excessive activation of fibroblasts with deposition of the extracellular matrix, which is also an element of the myocardial remodeling. The progression of heart failure is also associated with a mismatch between blood supply and myocardial oxygen demand, since an increase in the size of the CMCs is accompanied by a rarefaction of the intramural network of microvessels. It is believed that the violation of the ratio of the size of the heart, angiogenesis and cardiac function are the basis for the transition of adaptive compensation of the heart to decompensation with the progression of heart failure. Objective: to study morphological changes in the myocardium of the LV and LA in patients with mitral valve insufficiency. Materials and methods. Macroscopically, the condition of the myocardium was studied on the material of 14 autopsies of patients who died of NdMK insufficiency. History of NdMK – from 3 months. up to 2.4±1.1 years. As a control, the hearts of 3 deaths without cardiopathology were studied. The material for light microscopy was pieces of myocardium from different segments of the left ventricle, as well as from the walls of the left ventricle, obtained during autopsy.Morphological (macroscopic, histological and electron microscopic), morphometric and statistical research methods were used. Results. With LV dilatation associated with chronic mitral valve insufficiency, lengthening of each CMCs provides an increase in the area of ​​the myocardial walls, and, accordingly, the size of the cavity of the corresponding chamber of the heart, which compensates to some extent for the increase in diastolic blood volume in the LV and systolic blood volume in the LA. However, the factor limiting this compensation mechanism is the deficiency of the myocardial microvasculature associated with limited capillary growth. The contradiction between the need for the myocardium to lengthen the CMCs and the inability of capillaries to provide them with oxygen leads to a breakdown in compensation with an increase in fibrotic changes. This is a factor limiting the further increase in the volume of the cavity. Conclusions. Overloading of the myocardium with volume leads to an increase in the length of the CMCs, on average, from 57.3±9.1 µm to 93.7±12.4 µm. The increase in the length of the CMCs is due to the increase in the number of sarcomeres from 43.7±8.4 to 62.5±14.5. The diameter of the CMCs in this case does not increase reliably. Overloading of the heart cavities with volume is often accompanied by desynchronization of the CMCs contraction, which leads to disruption of the integrity of the myocytic "working syncytium" and pronounced interstitial fibrosis.

scholarly journals Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Vladimir Voskoboinick ◽  
Oleksandr Voskoboinyk ◽  
Oleg Chertov ◽  
Andrey Voskoboinick ◽  
Lidiia Tereshchenko
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Second Harmonic ◽  
Pure Water ◽  
Pressure Fluctuations ◽  
Pulsating Flow ◽  
Absolute Pressure ◽  
Flow Through ◽  
Hydrodynamic Noise ◽  
Pulsating Jets

Experimental research results of hydrodynamic noise of pulsating flow through a bileaflet mechanical mitral valve are presented. The pulsating flow of pure water corresponds to the diastolic mode of the cardiac rhythm heart. The valve was located between the model of the left atrium and the model of the left ventricle of the heart. A coordinate device, on which a block of miniature sensors of absolute pressure and pressure fluctuations was installed, was located inside the model of the left ventricle. It is found that the hydrodynamic noise of the pulsating side jet of the semiclosed valve is higher than for the open valve. The pressure fluctuation levels gradually decrease with the removal from the mitral valve. It is established that at the second harmonic of the pulsating flow frequency, the spectral levels of the hydrodynamic noise of the semiclosed bileaflet mechanical mitral valve are almost 5 times higher than the open valve. With the removal from the mitral valve, spectral levels of hydrodynamic noise are decreased, especially strongly at the frequency of the pulsating water flow and its higher harmonics.

scholarly journals Features of structural and geometric remodeling of the heart and changes in the diastolic filling of the heart in patients with chronic heart failure of ischemic genesis with preserved left ventricular ejection fraction

2021 ◽  
Vol 14 (1) ◽  
pp. 93-102
Author(s):  
V. A. Lysenko ◽  
M. S. Potapenko ◽  
V. V. Syvolap
Keyword(s):  
Heart Failure ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Diastolic Function ◽  
Ventricular Dysfunction ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Lv Mass ◽  
Diastolic Left Ventricular Dysfunction

Chronic heart failure (CHF) is the most common cardiovascular disease worldwide, estimated at 23 million. With the increase in the growing of the elderly population, the prevalence of hypertension, atrial fibrillation, obesity, diabetes, as well as the improvement of ultrasound diagnostic methods, a further increase in the number of cases of CHF with preserved left ventricular EF. Despite the large number of studies dedicated to analyzing the features of structural and geometric remodeling of the heart, changes in the systolic and diastolic function of the ventricles in patients with CHF, this issue hasn’t been definitively resolved and needs further improvement. The aim of the work – to investigate changes in structural and geometric parameters and diastolic function of the heart in patients with CHF of ischemic origin with preserved LV EF. Materials and methods. The study was included 43 patients (men – n = 19; women – n = 24) for CHF of ischemic origin with preserved LV EF, with sinus rhythm, stage II AB, II-IV FC for NYHA (main group), and 90 patients on coronary heart disease without signs of CHF (men – n = 40 (44.5 %); women – n = 50 (55.5 %)), (comparison group). Groups of patients were comparable in age, sex, height, weight, body surface area. Doppler echocardiographic examination was performed on the device Esaote MyLab Eight (Italy). Results. In patients with CHF preserved LV EF, the indicators prevailed: the size of the LA by 25 % (P = 0.005), the long axis of the LA by 11 % (P = 0.001), the LV EDV index of the LV by 13 % (P = 0.042), the LV mass index by 16 % (P = 0.013) according to the Penn Convention and (P = 0.004) the ASE. Eccentric left ventricular hypertrophy was diagnosed in 56 % of patients. Diastolic left ventricular dysfunction was absent in 2 % of patients with CHF. In 72 % of cases, the type of “relaxation disorder” was established, and in 26 % – “pseudonormal” LV filling profile. In none of the cases was a “restrictive” LV filling profile recorded. The following indicators of left ventricular diastolic function were lower in patients with CHF: e’ of the medial fibrous ring of the mitral valve by 26 % (P = 0.0001) and e’ lateral by 21 % (P = 0.0001), and the A’ the medial fibrous ring of mitral valve by 9 % (P = 0.022), and greater ratios of velocities E/e’ medial by 41 % (P = 0.0001), and E/e’ lateral fibrous ring of the mitral valve by 28 % (P = 0.0001), mean E/e’ by 36 % (P = 0.0001), which indicates a significant increase in end-diastolic pressure in the left ventricle. Conclusions. Structural and geometric remodeling of the heart in patients with CHF with preserved LV EF was characterized by dilatation of the left atrium, a moderate increase in the LV EDV index by 13 % (P = 0.042), a 16 % increase (P = 0.013) in the LV mass index, with the formation eccentric (56 %) and concentric (18 %) LV hypertrophy. Diastolic left ventricular dysfunction was absent in 2 % of patients with CHF. Disorders of diastolic filling of the left ventricle (72 % “relaxation disorder” and 26 % “pseudonormal” type) were occurred due to an increase in end-diastolic pressure in the left ventricle (increase by 41 % (P = 0.0001) ratio E/e’ medial fibrous ring MK), in LA (increase of more than 2 times (P = 0.0001) pulmonary capillary wedge pressure), and was accompanied by the development of postcapillary pulmonary hypertension (increase by 34 % (P = 0.0001) systolic pressure in the pulmonary artery). Despite the preserved LV EF, patients with CHF had significantly lower left and right ventricular contractility (10 % MAPSE med (P = 0.031), 18 % S med (P = 0.001) and 19 % (P = 0.007) RV EF).

Extended Myectomy for Hypertrophic Obstructive Cardiomyopathy

2012 ◽  
Vol 15 (5) ◽  
pp. 251
Author(s):  
Changqing Gao ◽  
Chonglei Ren ◽  
Cangsong Xiao ◽  
Yang Wu ◽  
Gang Wang ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Mitral Regurgitation ◽  
Surgical Procedures ◽  
Hypertrophic Obstructive Cardiomyopathy ◽  
Systolic Anterior Motion ◽  
Anterior Leaflet ◽  
Septal Myectomy ◽  
The Mean

<p><b>Background:</b> The purpose of this study was to summarize our experience of extended ventricular septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM).</p><p><b>Methods:</b> Thirty-eight patients (26 men, 12 women) with HOCM underwent extended ventricular septal myectomy. The mean age was 36.3 years (range, 18-64 years). Diagnosis was made by echocardiography. The mean (mean � SE) systolic gradient between the left ventricle (LV) and the aorta was 89.3 � 31.1 mm Hg (range, 50-184 mm Hg) according to echocardiographic assessments before the operations. Moderate or severe systolic anterior motion (SAM) of the anterior leaflet of the mitral valve was found in 38 cases, and mitral regurgitation was present in 29 cases. Extended ventricular septal myectomy was performed in all 38 cases. The results of the surgical procedures were evaluated intraoperatively with transesophageal echocardiography (TEE) and with transthoracic echocardiography (TTE) at 1 to 2 weeks after the operation. All patients were followed up with TTE after their operation.</p><p><b>Results:</b> All patients were discharged without complications. The TEE evaluations showed that the mean systolic gradient between the LV and the aorta decreased from 94.8 � 35.6 mm Hg preoperatively to 13.6 � 10.8 mm Hg postoperatively (<i>P</i> = .0000) and that the mean thickness of the ventricular septum decreased from 28.3 � 7.9 mm to 11.8 � 3.2 mm (<i>P</i> = .0000). Mitral regurgitation and SAM were significantly reduced or eliminated. During the follow-up, all patients promptly became completely asymptomatic or complained of mild effort dyspnea only, and syncope was abolished. TTE examinations showed that the postoperative pressure gradient either remained the same or diminished.</p><p><b>Conclusions:</b> Extended ventricular septal myectomy is mostly an effective method for patients with HOCM, and good surgical exposure and thorough excision of the hypertrophic septum are of paramount importance for a successful surgery.</p>

Left ventricle enlargement and increased systolic velocity in the mitral valve are indirect markers of the hepatopulmonary syndrome

2011 ◽  
Vol 31 (9) ◽  
pp. 1388-1394 ◽  
Author(s):  
Sophia Pouriki ◽  
Alexandra Alexopoulou ◽  
Christina Chrysochoou ◽  
Leonidas Raftopoulos ◽  
George Papatheodoridis ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Hepatopulmonary Syndrome
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