Analysis of the pathological severity degree of aortic stenosis (AS) and mitral stenosis (MS) using the discrete wavelet transform (DWT)

The heart is the principal organ that circulates blood. In normal conditions it produces four sounds for each cardiac cycle. However, most often only two sounds appear essential: S1 and S2. Two other sounds: S3 and S4, with lower amplitude than S1 or S2, appear occasionally in the cardiac cycle by the effect of disease or age. The presence of abnormal sounds in one cardiac cycle provide valuable information on various diseases. The aortic stenosis (AS), as being a valvular pathology, is characterized by a systolic murmur due to a narrowing of the aortic valve. The mitral stenosis (MS) is characterized by a diastolic murmur due to a reduction in the mitral valve. Early screening of these diseases is necessary; it’s done by a simple technique known as: phonocardiography. Analysis of phonocardiograms signals using signal processing techniques can provide for clinicians useful information considered as a platform for significant decisions in their medical diagnosis. In this work two types of diseases were studied: aortic stenosis (AS) and mitral stenosis (MS). Each one presents six different cases. The application of the discrete wavelet transform (DWT) to analyse pathological severity of the (AS and MS was presented. Then, the calculation of various parameters was performed for each patient. This study examines the possibility of using the DWT in the analysis of pathological severity of AS and MS.     

Implications of third heart sounds in patients with valvular heart disease. The Veterans Affairs Cooperative Study on Valvular Heart Disease.

BACKGROUND. The presence of third heart sounds in patients with valvular heart disease is often regarded as a sign of heart failure, but it may also depend on the type of valvular disease. METHODS. We assessed the prevalence of third heart sounds and the relation between third heart sounds and cardiac function in 1281 patients with six types of valvular heart disease. RESULTS. The prevalence of third heart sounds was higher in patients with mitral regurgitation (46 percent) or aortic regurgitation (28 percent) than in those with aortic stenosis (11 percent) or mitral stenosis (8 percent). The left ventricular ejection fraction was significantly lower (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (0.38, vs. 0.56 in those without third heart sounds) or mixed aortic valve disease (0.40 vs. 0.55). However, the ejection fraction was only slightly lower in patients with mitral regurgitation and third heart sounds (0.51 vs. 0.57, P = 0.03). The pulmonary-capillary wedge pressure was higher (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (18.6 mm Hg, vs. 12.1 mm Hg in those without third heart sounds). There was no association between the wedge pressure and third heart sounds in patients with mitral regurgitation. The prevalence of third heart sounds increased with the severity of mitral regurgitation. CONCLUSIONS. In patients with mitral regurgitation, third heart sounds are common but do not necessarily reflect left ventricular systolic dysfunction or increased filling pressure. In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence of systolic dysfunction and elevated filling pressure.     

Cardiac sound murmurs classification with autoregressive spectral analysis and multi-support vector machine technique

In this paper, a novel cardiac sound spectral analysis method using the normalized autoregressive power spectral density (NAR-PSD) curve with the support vector machine (SVM) technique is proposed for classifying the cardiac sound murmurs. The 489 cardiac sound signals with 196 normal and 293 abnormal sound cases acquired from six healthy volunteers and 34 patients were tested. Normal sound signals were recorded by our self-produced wireless electric stethoscope system where the subjects are selected who have no the history of other heart complications. Abnormal sound signals were grouped into six heart valvular disorders such as the atrial fibrillation, aortic insufficiency, aortic stenosis, mitral regurgitation, mitral stenosis and split sounds. These abnormal subjects were also not included other coexistent heart valvular disorder. Considering the morphological characteristics of the power spectral density of the heart sounds in frequency domain, we propose two important diagnostic features Fmax and Fwidth, which describe the maximum peak of NAR-PSD curve and the frequency width between the crossed points of NAR-PSD curve on a selected threshold value (THV), respectively. Furthermore, a two-dimensional representation on (Fmax, Fwidth) is introduced. The proposed cardiac sound spectral envelope curve method is validated by some case studies. Then, the SVM technique is employed as a classification tool to identify the cardiac sounds by the extracted diagnostic features. To detect abnormality of heart sound and to discriminate the heart murmurs, the multi-SVM classifiers composed of six SVM modules are considered and designed. A data set was used to validate the classification performances of each multi-SVM module. As a result, the accuracies of six SVM modules used for detection of abnormality and classification of six heart disorders showed 71-98.9% for THVs=10-90% and 81.2-99.6% for THVs=10-50% with respect to each of SVM modules. With the proposed cardiac sound spectral analysis method, the high classification performances were achieved by 99.9% specificity and 99.5% sensitivity in classifying normal and abnormal sounds (heart disorders). Consequently, the proposed method showed relatively very high classification efficiency if the SVM module is designed with considering THV values. And the proposed cardiac sound murmurs classification method with autoregressive spectral analysis and multi-SVM classifiers is validated for the classification of heart valvular disorders.     

超声心动图用于风湿性心脏病二尖瓣狭窄的临床分析

目的 研究超声心动图用于风湿性心脏病二尖瓣狭窄中的价值。方法 回归分析2017年1月~2018年1月在我院诊治的46例风湿性心脏病二尖瓣狭窄患者临床资料,研究其超声心动图临床特点。结果 46例患者中轻度狭窄19例（41.30%）、中度狭窄23例（50.00%）、重度狭窄4例（8.69%）。结论 采用超声心动图诊断风湿性心脏病二尖瓣狭窄,不仅对患者无创伤,而且操作简单、方便。同时可以判断出病情的严重程度,对临床诊治风湿性心脏病二尖瓣狭窄具有重要的价值。     

Feature Extraction for Systolic Heart Murmur Classification

Heart murmurs are often the first signs of pathological changes of the heart valves, and they are usually found during auscultation in the primary health care. Distinguishing a pathological murmur from a physiological murmur is however difficult, why an “intelligent stethoscope” with decision support abilities would be of great value. Phonocardiographic signals were acquired from 36 patients with aortic valve stenosis, mitral insufficiency or physiological murmurs, and the data were analyzed with the aim to find a suitable feature subset for automatic classification of heart murmurs. Techniques such as Shannon energy, wavelets, fractal dimensions and recurrence quantification analysis were used to extract 207 features. 157 of these features have not previously been used in heart murmur classification. A multi-domain subset consisting of 14, both old and new, features was derived using Pudil’s sequential floating forward selection (SFFS) method. This subset was compared with several single domain feature sets. Using neural network classification, the selected multi-domain subset gave the best results; 86% correct classifications compared to 68% for the first runner-up. In conclusion, the derived feature set was superior to the comparative sets, and seems rather robust to noisy data.     

Design of a Miniature Tissue Culture System to Culture Mouse Heart Valves

Valvular heart disease is a leading cause of morbidity and mortality in adults but little is known about the underlying etiology. A better understanding of the genetic and hemodynamic mechanisms involved in growth and remodeling of heart valves during physiological and pathological conditions is needed for a better understanding of valvular heart disease. Here, we report the design of a miniature tissue culture system (MTCS) that allows the culture of mitral valves from perinatal to adult mice. The design of the MTCS is novel in that fine positioning and cannulation can be conducted with hearts of different sizes (perinatal to adult). Perfusion of the heart and hence, culture of the mitral valve in its natural position, occurs in a hydraulically sealed culture bath environment. Using the MTCS, we successfully cultured the mitral valve of adult mouse hearts for 3 days. Histological analysis indicated that the cultured valves remained viable and their extracellular matrix organization was similar to age-matched native valves. Gene expression could also be modified in cultured valves by perfusion with medium containing beta-galactosidase-expressing adenovirus. Thus, the MTCS is a new tool to study the genetic and hemodynamic mechanisms underlying the three-dimensional organization of the heart valves, which could provide insights in the pathology of valvular heart disease and be used in animal models for the development of tissue-engineered heart valves.     

二尖瓣狭窄下游湍流剪应力体内多普勒超声定量检测的方法学研究

为建立与计算机图像分析技术相结合的人体二尖瓣狭窄下游湍流剪应力 (Turbulent shear stree,TSS)多普勒超声定量检测方法。本研究采用多普勒超声技术对正常人和不同程度二尖瓣狭窄病人组的二尖瓣下游血流速度频谱等指标进行多位点记录 ,通过计算机图像分析技术 ,测算出相关位点 TSS大小。结果表明不同程度二尖瓣狭窄组的二尖瓣下游核心位点 TSS与相对扰动强度 (Relative turbulent intensity,Irel)始终低于边界各位点 ;边界位点 TSS、Irel和流场均匀性等指标在正常对照和不同程度狭窄组之间均存在显著性差异 (P<0 .0 5 ) ,并均与有效瓣口面积 (Effective orifice area,EOA)明显相关。结论为二尖瓣有效开口面积越小 ,狭窄越重 ,射流边界 TSS和 Irel越大 ,射流核心区 TSS明显低于边界。研究结果显示 :应用与计算机图像分析相结合的多普勒超声技术所测人体二尖瓣狭窄下游 TSS与流场均匀性等常规多普勒超声指标具有良好的相关性 ,能共同反映不同狭窄程度病人瓣区血流动力学变化 ,因此表明本方法能比较准确地刻画人体二尖瓣狭窄下游 TSS的大小 ,并且 ,还具有安全无创、抗干扰能力强的特点 ,可用于瓣膜病病人瓣区流场中 TSS的定量分析。     

Biopsy of the heart valves. 872 cases

In this study, 872 heart valves surgically excised from 810 patients during a period of 5 years (1994 through 1998) were examined pathologically. There was a predominance of aortic (506 patients) versus mitral valves (246 pts.). While aortic valves came more often from men (364) than from women (142), in mitral valves the M:F ratio is 82/164. Isolated calcific aortic stenosis appeared as the most frequent valvular disease (418 pts.), with predominance of its sclerotic-senile type (238 pts.). Mitral stenosis (185 pts.) remains the classical post-rheumatic disease. The relative frequency of a subvalvular stenosing mitral lesion is stressed. The "pure" incompetence of both aortic (70 pts.) and mitral (56 pts.) valve was usually based on valvular myxoid degeneration. An aorto-mitral disease requiring replacement of both valves (51 pts.) presented typically as a post-rheumatic lesion, however, a combination of a post-rheumatic mitral with a degenerative-sclerotic aortic valve disease may be possible. In 30 patients, the valvular replacement was performed for infective endocarditis or a post-IE lesion, mostly of the aortic valve. With the almost non-existence of acute rheumatic fever and with the increasing average age of population in this country, we may expect a long-term decline in mitral valve disease and an increase in aortic valve disease, particularly in the sclerotic type of aortic stenosis.     

Incidental in vivo detection of an epithelioid hemangioendothelioma of the mitral valve

Valvular epithelioid hemangioendotheliomas (EHE) are exceptional. To the authors' knowledge only four cases have been reported. Herein is described an EHE incidentally detected in the mitral valve of a 69-year-old woman with chronic rheumatic valvular heart disease. The 0.4 cm lesion was situated in the anterior leaflet and was discovered in the pathological study after mitral valve replacement. The patient was alive and well 6 months after operation. Review of the literature including the present report, revealed that the mean age was 60.2 years (range, 49-69 years). Symptomatic patients had clinical features of valvular disease or embolism. Each of the four cardiac valves can be affected. Mean tumor size was 2.4 cm (range, 0.4-8 cm). In 40% of cases the EHE was an incidental finding at autopsy or in a removed valve. In two cases the involved cusp was affected by chronic rheumatic disease. In conclusion, EHE is a rare lesion that can be an incidental finding and it should be considered in the differential diagnosis of valve tumors. Although EHE can present a histologically benign appearance, the correct pathological diagnosis is clinically important because the lesion can be potentially malignant. Regular follow up is suggested due to this potential.     

Etiology of acquired valvular heart disease in adults. A survey of 18,132 autopsies and 100 consecutive valve-replacement operations

The cardiac valve pathology in 18,132 autopsies was analyzed. A total of 1,136 patients (6.3%) had acquired valvular disease. The most commonly diseased cardiac valve was the mitral valve (49%), followed by the aortic valve (42%) and the tricuspid (9%) and pulmonary valves (0.3%). Rheumatic fever accounted for 99.7% of cases of mitral stenosis and 68.4% of mitral incompetence. The autopsy incidence of mitral stenosis remained constant over 30 years (1950 to 1979). Only 44.4% of the cases of acquired aortic stenosis were due to rheumatic fever. Review of 100 consecutive, surgically excised native valves revealed that if the pathologist is given adequate information regarding the macroscopic appearance of the intact valve prior to excision, an accurate etiopathologic diagnosis can be made in 81% of cases compared with only 35% of cases without such information.     

Pathology of the cardiovascular system--new findings

Presented is a review of important new informations in the field of cardiovascular pathology. The particular items discussed are hypertension (new definition and classification), etiopathogenesis of atherosclerosis, ischemic heart disease (unstable plaque; acute coronary syndrome; advances in therapy), valvular diseases (changing spectrum; calcific aortic stenosis; mitral valve prolapse), cardiomyopathies (new definition; etiology), infective endocarditis (changing pattern), senile heart diseases, and endomyocardial biopsy.     

Matrix decomposition based feature extraction for murmur classification

Heart murmurs often indicate heart valvular disorders. However, not all heart murmurs are organic. For example, musical murmurs detected in children are mostly innocent. Because of the challenges of mastering auscultation skills and reducing healthcare expenses, this study aims to discover new features for distinguishing innocent murmurs from organic murmurs, with the ultimate objective of designing an intelligent diagnostic system that could be used at home. Phonocardiographic signals that were recorded in an auscultation training CD were used for analysis. Instead of the discrete wavelet transform that has been used often in previous work, a continuous wavelet transform was applied on the heart sound data. The matrix that was derived from the continuous wavelet transform was then processed via singular value decomposition and QR decomposition, for feature extraction. Shannon entropy and the Gini index were adopted to generate features. To reduce the number of features that were extracted, the feature selection algorithm of sequential forward floating selection (SFFS) was utilized to select the most significant features, with the selection criterion being the maximization of the average accuracy from a 10-fold cross-validation of a classification algorithm called classification and regression trees (CART). An average sensitivity of 94%, a specificity of 83%, and a classification accuracy of 90% were achieved. These favorable results substantiate the effectiveness of the feature extraction methods based on the proposed matrix decomposition method.     

Left ventricular cellular hypertrophy in pressure- and volume-overload valvular heart disease

To determine the dependence of myocyte hypertrophy in chronic valvular heart disease on the site and type of lesion, the myocardium was studied from 11 patients with either pressure-overload hypertrophy (PO; four patients with aortic stenosis and two with mixed aortic stenosis/insufficiency) or pure volume-overload hypertrophy (VO; two patients with mitral regurgitation and three with aortic insufficiency). These patients, all without coronary artery disease, died zero to 34 days after valve replacement surgery. Diameters of 25 longitudinally oriented myocytes in the circular midwall myocardium were measured with a calibrated light microscope eyepiece reticle on each of five transmural, transverse, histologic sections from the apical, anterolateral, posterolateral, anteroseptal, and posteroseptal left ventricle. Statistical analysis by modified two-way analysis of variance (ANOVA) demonstrated that mean myocyte size (based on 125 measurements) varied widely among cases but was not statistically different among sites. The myocyte diameter for PO lesions (25.9 +/- 1.1 micron, mean +/- SEM) was significantly greater (P less than 0.05) than that for pure VO lesions (20.4 +/- 0.7 micron), despite equal relative heart weights (measured/predicted from body weight: 2.5 +/- 0.2 [mean +/- SD] versus 2.5 +/- 0.5). This study suggests that 1) cellular hypertrophy in valvular heart disease occurs uniformly throughout the left ventricular myocardium; and 2) mean myocyte diameters are greater in PO than in VO hypertrophy for equivalent cardiac enlargement.     

High prevalence of amyloid in 150 surgically removed heart valves—a comparison of histological and clinical data reveals a correlation to atheroinflammatory conditions

IntroductionThe prevalence, pathophysiology, and clinical indicators of valvular amyloid deposition have not been clarified yet.MethodsOne hundred fifty surgically resected heart valve specimens [67.4±1.0 years; aortic stenosis (AS), n=100; aortic regurgitation, n=19; mitral stenosis, n=7; mitral regurgitation, n=24] were qualitatively, semiquantitatively, and immunohistochemically analyzed and correlated with clinical data.ResultsAmyloid was found in 83/150 specimens with highest prevalence in AS (74/100), intermediate prevalence in mitral stenosis (2/7) and regurgitation (7/24), and lowest prevalence in aortic regurgitation (2/19). Severe and polymorphic amyloid deposits were almost exclusively found in AS (35/100). Filamentous cloudy amyloid patterns occurred with the same frequency in AS (29/100). A combination of both was found only in AS (n=7/100). By immunohistochemistry, none of the most common amyloid proteins was identified except for a weak staining by the apolipoprotein AI antibody, but more intense adjacent to amyloid deposits. Amyloid correlated with valvular thickening (P<.05), hyperlipidemia (P=.07), coronary artery disease (P=.084), and obesity (P=.082).ConclusionsLocalized valvular amyloid is predominantly found in stenotic aortic valves. It appears to depend on atheroinflammatory conditions and high shear-stress hemodynamics. Further studies are needed to identify the underlying protein.     

Cronic non-rheumatic valvular heart disease. An autopsy study.

The frequency of chronic non-rheumatic valvular heart disease in Iceland was investigated via autoposies performed from November 1965 through December 1974. During this period, about 12.400 Icelanders died at the age of 16 years and older and 28.8 per cent of these were included in the study. At autopsy, males outnumbered females by 2:1. The frequency of calcific aortic stenosis was found to be 3.63 per cent and the prevalence was calculated to be 3.17 per cent among males and 4.50 per cent among females. Calcific aortic stenosis in tricuspid valves was more frequent in females and calcific aortic stenosis in bicuspid valves was more frequent in males. Among the hearts with calcific aortic stenosis, 70.8 per cent were found to have normally tricuspid valves, 25.4 per cent bicuspid valves and 3.8 per cent tricuspid valves with an unicommissural fusion. In 0.59 per cent of the hearts the aortic valve was either bicuspid or had an uncommissural fusion without the features of calcific stenosis. However, a functional stenosis was suggested by the increased weight of most of these hearts. The frequency of bicuspid aortic valves was 1.2 per cent with a prevalence in males of 1.54 per cent and in females 0.50 per cent. A calcified mitral annulus was found in 1.98 per cent of the hearts and in most, it was either associated with calcific aortic stenosis in a tricuspid valve, or it was a single valvular disease. Rheumatic valvular disease was found in 1.08 per cent of the heart examined.     

A wavelet-based optimal texture feature set for classification of brain tumours

In this work, the classification of brain tumours in magnetic resonance images is studied by using optimal texture features. These features are used to classify three sets of brain images—normal brain, benign tumour and malignant tumour. A wavelet-based texture feature set is derived from the region of interest. Each selected brain region of interest is characterized with both its energy and texture features extracted from the selected high frequency subband. An artificial neural network classifier is employed to evaluate the performance of these features. Feature selection is performed by a genetic algorithm. Principal component analysis and classical sequential methods are compared against the genetic approach in terms of the best recognition rate achieved and the optimal number of features. A classification performance of 98% is achieved in a genetic algorithm with only four of the available 29 features. Principal component analysis and classical sequential methods require a larger feature set to attain the similar classification accuracy of 98%. The optimal texture features such as range of angular second moment, range of sum variance, range of information measure of correlation II and energy selected by the genetic algorithm provide best classification performance with lower computational effort.     

与多普勒超声相结合的人体二尖瓣狭窄下游湍流剪应力二维有限元分析

目的 探讨一种与多普勒超声相结合的人体二尖瓣狭窄下游湍流剪应力地维有限元分析方法。方法 采用多普勒超声无创检测技术,将体内实时采集到的左心腔二维超声图像和左房、左室壁平均运动速度作为边界条件,对一组二尖瓣狭窄病人随访期间二尖瓣下游湍流剪应力（turbulent shear stress,TSS)进行计算机数值模拟、二维有限元分析。结果 有限元分析显示：TSS在两次随访前后均存在显著性差异（P＜0．05）,与瓣膜病变Wilkins评分呈明显正相关（r:0.80-0.82);无论病变和狭窄程度怎样,跨瓣血流核心区位点TSS始终低于边界各位点,其最大值＜80N／m^2,结果同以往研究结论一致。结论 二尖瓣狭窄下游所产生的TSS与瓣膜病变进展密切相关。有限元法对局部瓣区和整个流场中TSS和速度大小与分布的描述较为完整而详细,因此它与多普勒超声技术相结合,使心瓣流场中TSS的体内定量研究既全面而又准确。     

A wavelet-based optimal texture feature set for classification of brain tumours

In this work, the classification of brain tumours in magnetic resonance images is studied by using optimal texture features. These features are used to classify three sets of brain images - normal brain, benign tumour and malignant tumour. A wavelet-based texture feature set is derived from the region of interest. Each selected brain region of interest is characterized with both its energy and texture features extracted from the selected high frequency subband. An artificial neural network classifier is employed to evaluate the performance of these features. Feature selection is performed by a genetic algorithm. Principal component analysis and classical sequential methods are compared against the genetic approach in terms of the best recognition rate achieved and the optimal number of features. A classification performance of 98% is achieved in a genetic algorithm with only four of the available 29 features. Principal component analysis and classical sequential methods require a larger feature set to attain the similar classification accuracy of 98%. The optimal texture features such as range of angular second moment, range of sum variance, range of information measure of correlation II and energy selected by the genetic algorithm provide best classification performance with lower computational effort.     

基于定量影像组学的乳腺肿瘤良恶性诊断

乳腺癌是女性致死率最高的恶性肿瘤之一。为提高诊断效率,提供给医生更加客观和准确的诊断结果。借助影像组学的方法,利用公开数据集BreaKHis中82例患者的乳腺肿瘤病理图像,提取乳腺肿瘤病理图像的灰度特征、Haralick纹理特征、局部二值模式(LBP)特征和Gabor特征共139维影像组学特征,并用主成分分析(PCA)对影像组学特征进行降维,然后利用随机森林(RF)、极限学习机(ELM)、支持向量机(SVM)、k最近邻(kNN)等4种不同的分类器构建乳腺肿瘤良恶性的诊断模型,并对上述不同的特征集进行评估。结果表明,基于支持向量机的影像组学特征的分类效果最好,准确率能达到88.2%,灵敏性达到86.62%,特异性达到89.82%。影像组学方法可为乳腺肿瘤良恶性预测提供一种新型的检测手段,使乳腺肿瘤良恶性临床诊断的准确率得到很大提升。     

Pathology of surgically excised mitral valves. One hundred consecutive cases

In this study, 100 consecutive, surgically excised, mitral valves were examined pathologically. The valves were classified according to primary conditions that resulted in valvular malfunction. Rheumatic mitral valvular diseases (stenosis and/or insufficiency) accounted for 54% of the cases. Myxomatous changes (prolapse) were present in 32 cases. Fifty-nine percent (19 cases) of those cases with myxomatous changes also had chordal rupture. Four of the cases had papillary muscle rupture, and in seven cases, papillary muscle dysfunction occurred. In one case bacterial endocarditis was observed on a previously normal valve. In one case the pathology of valvular. In one case the pathology of valvular changes was indeterminant. Lupus erythematosus was diagnosed in one patient, and mitral valve insufficiency may have resulted as a complication.