Types Of Murmurs Research Articles

Prevalence and diagnostic characteristics of non-clinical mitral regurgitation murmurs in North American Whippets

ObjectivesTo assess the prevalence of functional ejection murmurs and murmurs of mitral regurgitation (MR) due to myxomatous mitral valve disease in healthy whippets; to assess the diagnostic value of auscultation to detect MR; and investigate the relationship between age and presence of echocardiographically documented MR (MRecho). AnimalsA total of 200 healthy client-owned Whippets, recruited at national shows between 2005 and 2009 were involved in this study. MethodsCross-sectional study. Dogs were examined by auscultation by one examiner and Doppler echocardiography by another, and results were compared. Prevalence of types of murmurs and MRecho were calculated and correlated to age. Accuracy of auscultation to predict MRecho was calculated. ResultsLeft-sided systolic heart murmurs were detected in 185/200 (93%) of dogs. Left apical systolic murmurs (Lapex) were detected in 57/200 (29%) and left basilar systolic murmurs (Lbase) in 128/200 of the dogs (64%). MRecho was present in 76/200 (38%) dogs. Prevalence MRecho was correlated with age (r = 0.96, p=0.0028). Mitral regurgitation detected by echocardiography was present in 12/78 (15%) of the dogs ≤ 2 years of age and in 59% of the dogs at 7–8 years old. Detection of Lapex predicted MRecho with sensitivity 65%, specificity 94%, positive predictive value 86%, and negative predictive value 81%; and accuracy improved when only dogs with more intense Lapex (grade ≥ 3/6) were considered. ConclusionsSystolic murmurs are common in North American Whippets and this breed exhibits a high prevalence of MRecho, which may be documented at a relatively early age. Whippets with non-clinical MRecho may not be identifiable by auscultation alone; echocardiographic examination may be required to exclude a diagnosis of MR. Louder heart murmurs allow more accurate localization in this population.

Multistage decision-based heart sound delineation method for automated analysis of heart sounds and murmurs.

A robust multistage decision-based heart sound delineation (MDHSD) method is presented for automatically determining the boundaries and peaks of heart sounds (S1, S2, S3, and S4), systolic, and diastolic murmurs (early, mid, and late) and high-pitched sounds (HPSs) of the phonocardiogram (PCG) signal. The proposed MDHSD method consists of the Gaussian kernels based signal decomposition (GSDs) and multistage decision-based delineation (MDBD). The GSD algorithm first removes the low-frequency (LF) artefacts and then decomposes the filtered signal into two subsignals: the LF sound part (S1, S2, S3, and S4) and the high-frequency sound part (murmurs and HPSs). The MDBD algorithm consists of absolute envelope extraction, adaptive thresholding, and fiducial point determination. The accuracy and robustness of the proposed method is evaluated using various types of normal and pathological PCG signals. Results show that the method achieves an average sensitivity of 98.22%, positive predictivity of 97.46%, and overall accuracy of 95.78%. The method yields maximum average delineation errors of 4.52 and 4.14 ms for determining the start-point and end-point of sounds. The proposed multistage delineation algorithm is capable of improving the delineation accuracy under time-varying amplitudes of heart sounds and various types of murmurs. The proposed method has significant potential applications in heart sounds and murmurs classification systems.

An automatic wavelet denoising scheme for heart sounds

Phonocardiograms (PCGs), recording of heart sounds, have many advantages over traditional auscultation in that they may be replayed and analyzed for spectral and frequency information. PCG is not a widely used diagnostic tool as it could be. One of the major problems with PCG is noise corruption. Many sources of noise may pollute a PCG signal including lung and breath sounds, environmental noise and blood flow noises which are known as murmurs. These murmurs contain many information on heart hemodynamic which can be used particularly in detecting of heart valve diseases. An automated system for heart murmurs processing can be an important tool in diagnostic of heart diseases using a simple electronic stethoscope. However, the first step before developing any automated system is the segmentation of the PCG signals from which the murmurs can be separated. A robust segmentation algorithm must have a robust denoising technique, where, wavelet transform (WT) is among the ones which exhibits very high satisfactory results in such situations. However, the selection of level of decomposition and the mother wavelet are the major challenges. This paper proposes a novel approach for an automatic selection of mother wavelet and level of decomposition that can be used in heart sounds denoising. The obtained results on both simulative and real PCG signals showed that the proposed approach can successfully select the best level of decomposition with the best mother wavelet that can be used in extraction operation of main PCG sound components (S1 and S2) from various types of murmurs.

Automatic diagnosis of septal defects based on tunable-Q wavelet transform of cardiac sound signals

Accurate and quick diagnosis of cardiac disorders like septal defects can be performed by automatic analysis of cardiac sound signals using advanced signal processing methods. In this paper, we present a new method for diagnosis of septal defects from cardiac sound signals using tunable-Q wavelet transform (TQWT) based features. To start with, the established constrained TQWT based approach has been used to derive the heart beat cycles from cardiac sound signals. Then the TQWT based decomposition of segmented heart beat cycles has been performed up to a certain level. The combinations of sub-bands obtained from TQWT based decomposition can be used to extract the diagnostic features. The correlation between sub-bands can characterize the various types of murmurs in cardiac sound signals. Therefore, in order to represent the murmurs in cardiac sound signals, proposed feature set was obtained with sum of average magnitude difference function (SAMDF) that have been computed from reconstruction of decomposed sub-bands. In search of effective feature set based on SAMDF that could provide significant classification performance, various decomposition levels have been examined. Moreover, in order to establish the usefulness of the proposed method for diagnosis of septal defects, besides cardiac sound signals for septal defects and normal, this study covers signals to be detected for valvular defects and other defects like ventricular hypertrophy, constrictive pericarditis etc. as available from publicly available datasets. The classification has been performed using least squares support vector machine (LS-SVM) with different kernel functions. At each decomposition level under study, the effect of quality-factor (Q) of the TQWT from 1 to 50 on classification performance has been evaluated. Moreover, in order to show the effectiveness of the proposed method, results have been compared with existing method.

Antonio Maria Valsalva (1666 - 1723)

Antonio Maria Valsalva (1666 - 1723)

The "straight back" syndrome: current perspective more often associated with valvular heart disease than pseudoheart disease: a prospective clinical, electrocardiographic, roentgenographic, and echocardiographic study of 50 patients.

Fifty consecutive patients (36 male, 14 female, mean age 28 years) who had heart murmurs and clinical and radiographic evidence of straight upper dorsal spine (straight back syndrome, SBS) underwent detailed clinical, electrocardiographic, roentgenographic, and echocardiographic evaluation. Palpable systolic thrill noted in one (2%) and widened S2 with persistent splitting in 2 (4%) patients were uncommon. Murmurs were invariably systolic in nature. Those located at the base of the heart in 19 (38%) patients were ejection in type and best heard during expiration. Those located at the apex in 26 (52%) patients were either mid-, late-, or pansystolic, and often associated with midsystolic click. Five (10%) patients had both types of murmurs. Diastolic murmurs were not heard in any patient. EKGs were normal in the majority. Cardiomegaly (C:T greater than 55%) was present in only 5 (10%) and dilatation of the main pulmonary artery in 2 (4%) patients. Thus the incidence of pseudoheart disease (PsHD) was small (14%). Echocardiograms were normal in 18 (36%) and abnormal in 32 (64%) patients. There was evidence of mitral valve prolapse (MVP) in 29 (58%) patients and 3 (6%) had evidence of bicuspid aortic valve (BAV). In a control group of 40 age- and sex-matched patients (26 male, 14 female, mean age 29.5 years), who also had heart murmurs but lacked straight upper dorsal spine, only 7 (17.5%) had MVP and none had BAV. The difference is both clinically and statistically significant (p less than 0.001). It is concluded that SBS is more often associated with valvular heart disease (MVP and BAV) than PsHD. Therefore, the diagnosis of SBS should remain presumptive until echocardiography has been performed to exclude MVP and BAV. SBS patients who have valvular heart disease should receive infective endocarditis prophylaxis.

Study by cathode-ray oscillography of some innocent and pathologic cardiac murmurs of children

Cardiac murmurs of several types found in children and adolescents have been recorded on magnetic tape and examined by cathode-ray oscillography. The types of murmurs studied have included two presumably innocent types of murmurs, the precordial vibratory (“twanging-string” murmur of Still) and the pulmonic-systolic murmur, which comprise the great majority of nonpathologic murmurs of childhood, and several types of organic murmurs, those due to aortic and mitral insufficiency and to a variety of congenital malformations. In terms of wave form, the precordial vibratory murmurs examined showed a discernible basic wave of frequency ranging from 90 to 180 cycles per second, among various subjects, with a small and variable degree of distortion. In oscillograms of pulmonic-systolic murmurs a basic wave in the range of frequency given above could also be discerned, but the degree of distortion was noticeably greater than that found in the precordial vibratory murmurs. In the case of the specimens examined in all the groups of organic murmurs mentioned above the wave forms were highly complex, with no detectable basic wave or recognizable pattern. A possible implication of these differences in wave form is discussed.

Early changes of mitral valve function in rheumatic heart disease: A clinical, phonocardiographic and electrokymographic study

A clinical and graphic study was made of fifty-three cases of rheumatic fever. The patients were studied by means of phonocardiograms and electrokymograms of the left auricle. Thirty patients were studied again after an interval of four to six months. The patients were divided into three groups: (1) those with questionable rheumatic fever, or rheumatic fever without clinical cardiac damage; (2) those during the first attack of rheumatic fever, with clinical cardiac damage; and (3) those with recurrence of rheumatic fever. The phonocardiographic findings are analyzed and discussed. Two types of murmurs were the most common in the early stages of rheumatic fever: (1) A soft, high-pitched, apical, systolic murmur “in decrescendo”; (2) a harsher, at times musical, “diamond-shaped” pulmonic murmur. The mechanism of production of these murmurs is discussed. In the later stages of the disease the apical murmur was often louder while the pulmonic was often less apparent. If healing of the lesions had occurred, both murmurs were less apparent or disappeared. The electrokymogram in a high percentage of cases revealed a pattern due to transmission of intraventricular pressure to the left auricle on account of mitral regurgitation. The various myocardial and valvular elements causing this regurgitation are discussed. The correlation between clinical, phonocardiographic and electrokymographic data proved that these graphic studies are of definite help not only in establishing the diagnosis but also in evaluating the severity of the regurgitation and of the cardiac murmurs. Evaluation of the part played by muscular and valvular factors in causing regurgitation was not possible after a single examination. On the other hand, repeated examinations during and after the active stage frequently permitted such evaluation.