DIFFICULTIES IN EVALUATING SYSTOLIC MURMURS IN CHILDREN—With Special Reference to the Functional Systolic Murmur

As a guide in distinguishing between organic and functional systolic murmurs, five characteristics of a murmur should always be noted, namely, (a) the location of maximal intensity of the murmur; (b) the intensity of the murmur itself; (c) the character of the murmur, that is, whether it is blowing, rumbling, rough or harsh; (d) the transmission of the murmur; and (e) the duration of the murmur and its time within the cardiac cycle.Functional systolic murmurs may be found at any of the “valve areas,” are usually faint to moderately loud, are usually soft and blowing in quality, are usually only slightly transmitted, and are usually not heard immediately following the first heart sound.In doubtful cases, those in which history and physical examination alone are not sufficient to make a diagnosis of functional systolic murmur, further studies should be undertaken to determine the presence or absence of organic heart disease.Until a diagnosis of organic heart disease can be made with reasonable certainty, there should be no restriction of activity imposed, because of the likelihood of the development of cardiac neurosis in the patient.     

Wavelet processing of systolic murmurs to assist with clinical diagnosis of heart disease

Despite advances in imaging technologies for the heart, screening of patients for cardiac pathology continues to include the use of traditional stethoscope auscultation. Detection of heart murmurs by the primary care physician often results in the ordering of additional expensive testing or referral to cardiology subspecialists, although many of the patients are eventually found to have no pathologic condition. In contrast, auscultation by an experienced cardiologist is highly sensitive and specific for detecting heart disease. Although attempts have been made to automate screening by auscultation, no device is currently available to fulfill this function. Multiple indicators of pathology are nonetheless available from heart sounds and can be elicited using certain signal processing techniques such as wavelet analysis. Results presented here show that a signal of pathology, the systolic murmur, can reliably be detected and classified as pathologic using a portable electrocardiogram and heart sound measurement unit combined with a wavelet-based algorithm. Wavelet decomposition holds promise for extending these results to detection and evaluation of other audible pathologic indicators.     

PHONOCARDIOGRAPHY

In phonocardiography the second heart sound is important in appraisal of congenital heart disease and pulmonary hypertension because it reflects the duration of right ventricular systoles.The systolic murmur in patients with intracardiac shunt decreases as pulmonary hypertension develops, and may eventually disappear completely as the pulmonary pressure reaches systemic level.Reference tracings in phonocardiography are useful for showing the interrelationship of the various cardiac sounds and murmurs.     

Heart energy signature spectrogram for cardiovascular diagnosis

A new method and application is proposed to characterize intensity and pitch of human heart sounds and murmurs. Using recorded heart sounds from the library of one of the authors, a visual map of heart sound energy was established. Both normal and abnormal heart sound recordings were studied. Representation is based on Wigner-Ville joint time-frequency transformations. The proposed methodology separates acoustic contributions of cardiac events simultaneously in pitch, time and energy. The resolution accuracy is superior to any other existing spectrogram method. The characteristic energy signature of the innocent heart murmur in a child with the S3 sound is presented. It allows clear detection of S1, S2 and S3 sounds, S2 split, systolic murmur, and intensity of these components. The original signal, heart sound power change with time, time-averaged frequency, energy density spectra and instantaneous variations of power and frequency/pitch with time, are presented. These data allow full quantitative characterization of heart sounds and murmurs. High accuracy in both time and pitch resolution is demonstrated. Resulting visual images have self-referencing quality, whereby individual features and their changes become immediately obvious.     

心脏杂音的自适应时频谱分析

应用自适应时频分析方法对心脏杂音（收缩期杂音、舒张期杂音、连续性杂音）进行分类研究,旨在克服固定核时频分析分辨率较低的缺陷。对多例心脏病人不同类型的心脏杂音分析结果表明：基于自适应锥形核分布的时频谱反映了心脏杂音在时间－频率平面的能量分布及动态变化过程,并有较高的时频分辨率,不同类型心脏杂音的时频谱具有明显的时频特征。     

Occult aortic stenosis as cause of intractable heart failure

During a three-year period 10 patients with critical aortic stenosis were referred to a cardiac referral centre with symptoms and signs of intractable cardiac failure and low cardiac output. In nine patients the correct diagnosis was not suspected at the referring hospital, and in the remaining patient the true severity of the aortic stenosis was not appreciated and cardiomyopathy was suggested as an additional diagnosis. The most common referral diagnoses were severe mitral regurgitation (four patients), congestive cardiomyopathy (two patients), or both (three patients). Only two patients had soft ejection systolic murmurs at the base of the heart radiating into the neck, and such a murmur appeared in a third patient during medical treatment. The carotid pulses were of small volume but the characteristic slow-rising, anacrotic nature of the pulse could not be appreciated clinically. The diagnosis was suspected in nine patients because of aortic valve calcification detected by lateral chest x-ray examination in seven patients and by x-ray screening of the heart in two, and because of abnormal aortic valve echoes in the echocardiogram of all five patients in whom the aortic valve could be seen. Eight patients underwent aortic valve replacement despite seemingly poor preoperative left ventricular function. Three patients died, of whom two had severe coexistent coronary artery disease. The five survivors all returned to normal lives and needed little or no medication.Critical aortic stenosis should be actively sought in patients with severe heart failure of unknown cause since surgery may enable them to resume their normal lives.     

Analytical and numerical solutions of the potential and electric field generated by different electrode arrays in a tumor tissue under electrotherapy

Background

During the cardiac cycle, the heart normally produces repeatable physiological sounds. However, under pathologic conditions, such as with heart valve stenosis or a ventricular septal defect, blood flow turbulence leads to the production of additional sounds, called murmurs. Murmurs are random in nature, while the underlying heart sounds are not (being deterministic).

Innovation

We show that a new analytical technique, which we call Digital Subtraction Phonocardiography (DSP), can be used to separate the random murmur component of the phonocardiogram from the underlying deterministic heart sounds.

Methods

We digitally recorded the phonocardiogram from the anterior chest wall in 60 infants and adults using a high-speed USB interface and the program Gold Wave http://www.goldwave.com. The recordings included individuals with cardiac structural disease as well as recordings from normal individuals and from individuals with innocent heart murmurs. Digital Subtraction Analysis of the signal was performed using a custom computer program called Murmurgram. In essence, this program subtracts the recorded sound from two adjacent cardiac cycles to produce a difference signal, herein called a "murmurgram". Other software used included Spectrogram (Version 16), GoldWave (Version 5.55) as well as custom MATLAB code.

Results

Our preliminary data is presented as a series of eight cases. These cases show how advanced signal processing techniques can be used to separate heart sounds from murmurs. Note that these results are preliminary in that normal ranges for obtained test results have not yet been established.

Conclusions

Cardiac murmurs can be separated from underlying deterministic heart sounds using DSP. DSP has the potential to become a reliable and economical new diagnostic approach to screening for structural heart disease. However, DSP must be further evaluated in a large series of patients with well-characterized pathology to determine its clinical potential.     

A Study of Normal Heart Sounds,Heart Size,Arterial Pressure and Electrocardiograms From Infancy to Early Adulthood in One Male and One Female

This study forms part of a project to define the range of normal for heart sounds and murmurs. Using the method of writing quantitative symbol phonocardiograms, data were collected on one female and one male subject from earliest infancy to adulthood (aged 27 and 25). Serial measurements of heart size, arterial pressure and records of electrocardiograms and electrophonocardiograms were made. The heart sounds are shorter and somewhat less loud under the age of two years than later. Physiologic splitting of the first and second sounds, a physiologic systolic murmur, the appearance and disappearance of a third sound are shown in the illustrations which epitomize this study. These longitudinal studies of age period changes in the electrocardiogram reveal what has been learned from the horizontal studies. The shape of the cardiac silhouette as recorded between the ages of 5 and 8 years seems to predict the adult shape. The adult type of arterial pressure became established in the early teens.     

Congenital heart disease cyanotic children

Cyanosis is often the only apparent symptom of congenital heart disease for which a child is brought to a physician. Some of the more common anomalies can be diagnosed from this and other symptoms by a general practitioner. Squatting after exertion is a sign of tetralogy of Fallot; severe disability with relatively mild cyanosis may indicate pure pulmonary stenosis. A brisk, short, rasping systolic murmur is characteristic of these conditions and of tricuspid atresia. Tetralogy of Fallot is further symptomatized by a boot-shaped heart, not greatly enlarged, and right axis deviation on electrocardiograms. Typically the lung fields are clear. The author's treatment of choice is aortic-pulmonary or subclavian-pulmonary anastomosis as indicated, preferably done after the child is three years old if the condition is not so severe as to require earlier operation. Pure pulmonary stenosis, which in some cases cannot be distinguished from tetralogy of Fallot except by cardiac catheterization and angiocardiography, may in more typical cases be diagnosed by convexity rather than concavity in the pulmonary segment and by differences in electrocardiograms. An expanding valvulotome is used to open the stenosed pulmonary valve, which is then dilated.A systolic murmur, a round heart and left axis deviation are usually found in tricuspid atresia. Shunt operations performed for relief of this condition may lead to later heart failure because of the devious rerouting of blood through the heart. The operations here outlined and others are statistically evaluated.     

CONGENITAL HEART DISEASE IN CYANOTIC CHILDREN

Cyanosis is often the only apparent symptom of congenital heart disease for which a child is brought to a physician. Some of the more common anomalies can be diagnosed from this and other symptoms by a general practitioner. Squatting after exertion is a sign of tetralogy of Fallot; severe disability with relatively mild cyanosis may indicate pure pulmonary stenosis. A brisk, short, rasping systolic murmur is characteristic of these conditions and of tricuspid atresia.Tetralogy of Fallot is further symptomatized by a boot-shaped heart, not greatly enlarged, and right axis deviation on electrocardiograms. Typically the lung fields are clear. The author''s treatment of choice is aortic-pulmonary or subclavian-pulmonary anastomosis as indicated, preferably done after the child is three years old if the condition is not so severe as to require earlier operation.Pure pulmonary stenosis, which in some cases cannot be distinguished from tetralogy of Fallot except by cardiac catheterization and angiocardiography, may in more typical cases be diagnosed by convexity rather than concavity in the pulmonary segment and by differences in electrocardiograms. An expanding valvulotome is used to open the stenosed pulmonary valve, which is then dilated.A systolic murmur, a round heart and left axis deviation are usually found in tricuspid atresia. Shunt operations performed for relief of this condition may lead to later heart failure because of the devious rerouting of blood through the heart.The operations here outlined and others are statistically evaluated.     

Feature Extraction and Classification of Heart Murmurs Based on Acoustic Qualities

Background and objectiveHeart murmur characterization is a crucial part of cardiac auscultation for determining the potential etiology and severity of heart diseases. One such helpful murmur characterization is the sonic qualities, which reflect both structural and hemodynamical states of the heart. Therefore, the objective is to develop a machine learning based solution for classifying murmur qualities.MethodsFour medically defined murmur qualities, namely the musical quality, blowing-like quality, coarse quality, and soft quality were examined. Feature was extracted from heart murmurs signals in their time domain, frequency domain, time-frequency domain, and phase space domain. Sequential forward floating selection (SFFS) was implemented along with three classifiers, including k-nearest neighbor (KNN), Naïve-Bayes (NB), and linear support vector machine (SVM).ResultsIt was found that multi-domain features are suited for better classification results and linear SVM was able to achieve a better balance between performance and the size of feature subsets among tested classifiers. Using the derived features, classification accuracies of 86%, 91%, 90%, and 84% were achieved for musical quality, blowing-like quality, coarse quality, and soft quality classifications respectively.ConclusionsThe study demonstrated that it is possible to effectively characterize heart murmur through its diagnostic characteristics instead of drawing direct conclusions, which is helpful for retaining versatility and generality found in the conventional cardiac auscultation.     

Role of echocardiography in diagnosis and risk stratification in heart failure with left ventricular systolic dysfunction

Congestive heart failure with preserved left ventricular systolic function has emerged as a growing epidemic medical syndrome in developed countries, which is characterized by high morbidity and mortality rates. Rapid and accurate diagnosis of this condition is essential for optimizing the therapeutic management. The diagnosis of congestive heart failure is challenging in patients presenting without obvious left ventricular systolic dysfunction and additional diagnostic information is most commonly required in this setting. Comprehensive Doppler echocardiography is the single most useful diagnostic test recommended by the ESC and ACC/AHA guidelines for assessing left ventricular ejection fraction and cardiac abnormalities in patients with suspected congestive heart failure, and non-invasively determined basal or exercise-induced pulmonary capillary hypertension is likely to become a hallmark of congestive heart failure in symptomatic patients with preserved left ventricular systolic function. The present review will focus on the current clinical applications of spectral tissue Doppler echocardiography used as a reliable noninvasive surrogate for left ventricular diastolic pressures at rest as well as during exercise in the diagnosis of heart failure with preserved left ventricular systolic function. Chronic congestive heart failure, a disease of exercise, and acute heart failure syndromes are characterized by specific pathophysiologic and diagnostic issues, and these two clinical presentations will be discussed separately.     

Non-invasive algorithm for bowel motility estimation using a back-propagation neural network model of bowel sounds

Background

Although cardiac auscultation remains important to detect abnormal sounds and murmurs indicative of cardiac pathology, the application of electronic methods remains seldom used in everyday clinical practice. In this report we provide preliminary data showing how the phonocardiogram can be analyzed using color spectrographic techniques and discuss how such information may be of future value for noninvasive cardiac monitoring.

Methods

We digitally recorded the phonocardiogram using a high-speed USB interface and the program Gold Wave http://www.goldwave.com in 55 infants and adults with cardiac structural disease as well as from normal individuals and individuals with innocent murmurs. Color spectrographic analysis of the signal was performed using Spectrogram (Version 16) as a well as custom MATLAB code.

Results

Our preliminary data is presented as a series of seven cases.

Conclusions

We expect the application of spectrographic techniques to phonocardiography to grow substantially as ongoing research demonstrates its utility in various clinical settings. Our evaluation of a simple, low-cost phonocardiographic recording and analysis system to assist in determining the characteristic features of heart murmurs shows promise in helping distinguish innocent systolic murmurs from pathological murmurs in children and is expected to useful in other clinical settings as well.     

Evaluation of the Swedish breeding program for cavalier King Charles spaniels

A breeding program with the aim of reducing the prevalence of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCS) is currently ongoing in Sweden. In this investigation 353 CKCS were selected as a sample of the population and 150 were examined by auscultation for heart murmurs when they reached the age of six years in 2007 and 2009. The aim with this investigation was to study the prevalence of heart murmurs in six-year-old CKCS and to estimate if prevalence has decreased since the breeding program was introduced 2001. The effect of the breeding program was evaluated by comparing the prevalence of heart murmurs in the two groups. In 2007, the prevalence of heart murmurs was 52% (50% for females and 54% for males) and in 2009, the prevalence was 55% (44% for females and 67% for males). No significant difference was found in the prevalence of heart murmurs between 2007 and 2009 (P = 0.8). For all six-year-old CKCS, the prevalence of heart murmur was 53% (females 46% and males 61%), which is higher than previous Swedish investigations.     

Load-sensitive measures may overestimate global systolic function in the presence of left ventricular hypertrophy: a comparison with load-insensitive measures

Transgenic animal models have provided a vital insight into the pathogenesis of cardiovascular disease, but functional cardiac assessment is often limited by high heart rates and small heart size. We hypothesized that in the presence of concentric left ventricular (LV) hypertrophy (LVH), load-sensitive measures of contractility may be misinterpreted as overestimating global cardiac function, because the normal function of excess sarcomeres may displace a greater volume of blood during contraction. Conductance catheter technology was used to evaluate pressure-volume (P-V) relationships as a load-insensitive method of assessing cardiac function in vivo in 18-wk-old heterozygous (mRen-2)27 transgenic rats (a model of LVH), compared with age-matched Sprague-Dawley (SD) controls. Anesthetized animals underwent echocardiography followed by P-V loop analysis. Blood pressure, body weight, and heart rate were higher in the Ren-2 rats (P < 0.05). Load-sensitive measures of systolic function, including fractional area change, fractional shortening, ejection fraction, and positive peak rate of LV pressure development, were greater in the Ren-2 than control animals (P < 0.05). Load-insensitive measures of systolic function, including the preload recruitable stroke work relationship and the end-systolic P-V relationship, were not different between Ren-2 and SD rats. Regional wall motion assessed by circumferential shortening velocity suggested enhanced circumferential fiber contractility in the Ren-2 rats (P = 0.02), but tissue Doppler imaging, used to assess longitudinal function, was not different between groups. Although conventional measures suggested enhanced systolic function in the Ren-2 rat, load-insensitive measures of contractility were not different between Ren-2 and SD animals. These findings suggest that the normal range of values for load-sensitive indexes of contractility needs to be altered according to the degree of LVH. To accurately identify changes in systolic function, we suggest that a combination of echocardiography with assessment of load-insensitive measures be used routinely.     

Incidence of Heart Disease in Children in the City of Toronto

A special registry of children with heart disease in the City of Toronto was set up (a) to provide for follow-up of all children with heart disease in that community, (b) to remove the “cardiac” label from children with functional murmurs, (c) to acquaint parents with facilities available for the management of children with heart disease, and (d) to record useful data regarding heart disease in children.The 1961-62 Cardiac Registry showed that 542 of 156,775 pre-school and school children had evidence of heart disease; 464 were congenital and 68 rheumatic in origin: 121 children with congenital heart defects had been treated surgically. Congenital cardiac disease ranked fifth in frequency among the causes of death in children. There was a diminution of acute rheumatic fever and rheumatic heart disease in children in 1961-62 when compared with data for previous years. Seventy-eight per cent of children in this series with a history of rheumatic fever were receiving continuous prophylaxis.     

Clues in diagnosing congenital heart disease.

A number of practical office and bedside clues to cardiac disease in infants and children have been passed on through the years. They relate to the history, to the inspection and palpation components of the physical examination, and to knowledge of the specific cardiac defects that are likely to be associated with certain clinical syndromes. With the possible exception of coarctation of the aorta, the clues are not diagnostically specific. In many instances, however, they serve to narrow a broad array of diagnostic possibilities to 2 or 3 and, with the aid of other clues and auscultation, they can often be distinguished from one another. When a primary care physician is confronted with a child who has an incidental murmur that is "probably" innocent but could be organic, useful clues favoring an organic murmur are a history of congenital heart disease in a first-degree relative; a history of maternal rubella syndrome, alcohol use, or teratogenic drug use during pregnancy; a history of inappropriate sweating; a history of syncope, chest pain, or squatting; maternal diabetes mellitus; premature birth; birth at a high altitude; cyanosis; abnormal pulsations; recurrent bronchiolitis or pneumonia; chronic unexplained hoarseness; asymmetric facies with crying; and a physical appearance suggestive of a clinical syndrome.     

Reduced systolic wave generation and increased peripheral wave reflection in chronic heart failure

In human heart failure the role of wave generation by the ventricle and wave reflection by the vasculature is contentious. The aim of this study was to compare wave generation and reflection in normal subjects with patients with stable compensated heart failure. Twenty-nine normal subjects and 67 patients with heart failure (New York Heart Association class II or III) were studied by noninvasive techniques applied to the common carotid artery. Data were analyzed by wave intensity analysis to determine the nature and direction of waves during the cardiac cycle. The energy carried by an early systolic forward compression wave (S wave) generated by the left ventricle and responsible for acceleration of flow in systole was significantly reduced in subjects with heart failure (P < 0.001), and the timing of the peak of this wave was delayed. In contrast, reflection of this wave was increased in subjects with heart failure (P < 0.001), but the timing of reflections with respect to the S wave was unchanged. The energy of an expansion wave generated by the heart in protodiastole was unaffected by heart failure. The carotid artery wave speed and the augmentation index did not significantly differ between subjects with heart failure compared with normal individuals. The ability of the left ventricle to generate a forward compression wave is markedly impaired in heart failure. Increased wave reflection serves to maintain systolic blood pressure but also places an additional load on cardiac function in heart failure.     

The Diagnosis of Mitral Stenosis

The diagnosis of classical mitral stenosis is easy, but many pitfalls lead to over-diagnosis or under-diagnosis. These have been considered in detail and variations in symptoms and signs have been illustrated by case histories. Such variations include: (1) Embolism producing the Leriche syndrome; (2) mitral stenosis with insignificant hemodynamic effect; (3) myxoma masquerading as mitral stenosis; (4) mitral stenosis without apical murmurs, and (5) mitral stenosis with a systolic murmur predominant or alone. In cases of combined mitral and aortic stenosis, the history, radiographic configuration, and incidence of hemoptysis, edema, bronchitis, embolism and atrial fibrillation resemble such findings in cases of isolated mitral stenosis, but the auscultatory signs of the latter may be obscured. The degree of aortic stenosis is difficult to determine in cases of combined stenosis. In the diagnosis of re-stenosis the condition of the valve at the first commissurotomy, the precise procedure performed and the degree of regurgitation produced are of prime importance. Congenital mitral stenosis is rare and is associated with a high incidence of other defects.     

NT-proBNP and BNP values in cardiac patients with different degree of left ventricular systolic dysfunction

We investigated the performance of brain natriuretic peptides (BNP and NT-proBNP) in detecting various degrees of left ventricular systolic dysfunction. The NT-proBNP assay (Roche) and the BNP assay (Bayer Shionoria) were performed in 46 patients (mean age 50 years; range 20-79 years) with various types of heart disease (chronic heart failure due to coronary artery disease, cardiomyopathy, acquired valve disease, congenital heart diseases) and different impairment of left ventricular systolic dysfunction was assessed by echocardiography. Patients were divided into four groups according to the left ventricular ejection fraction (LVEF) correlated with clinical severity. Significant differences in medians of NT-proBNP and BNP values between all groups were determined (P= 0.0161 for NT-proBNP and P=0.0180 for BNP). For identifying patients with severe systolic dysfunction (LVEF<40%), receiver operating characteristic (ROC) analysis for both BNP and NT-proBNP was performed. The diagnostic performances expressed as areas under the curve were of 0.69 for NT-proBNP (cut off value 367 pg/ml) and 0.60 for BNP (cut off value 172 pg/ml). However, the BNP showed higher sensitivity (85 % vs. 63 %) and a higher positive predictive value (69 % vs 55 %) than the NT-proBNP. The negative predictive values of BNP and NT-proBNP were similar (70 % and 71 % respectively). Brain natriuretic peptides are promising markers for the diagnosis of severe left ventricular systolic dysfunction.