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Cardiovascular diseases (CVDs) are among the primary causes of mortality globally, highlighting the critical need for early detection to mitigate their impact. Phonocardiograms (PCGs), which record heart sounds, are essential for the non-invasive assessment of cardiac function, enabling the early identification of abnormalities such as murmurs. Particularly in underprivileged regions with high birth rates, the absence of early diagnosis poses a significant public health challenge. In pediatric populations, the analysis of PCG signals is invaluable for detecting abnormal sound waves indicative of congenital and acquired heart diseases, such as septal defects and defective cardiac valves. In the PhysioNet 2022 challenge, the murmur score is a weighted accuracy metric that reflects detection accuracy based on clinical significance. In our research, we proposed a mean teacher method tailored for murmur detection, making full use of the Phyionet2022 and Phyionet2016 PCG datasets, achieving the SOTA (State of Art) performance with a murmur score of 0.82 and an AUC score of 0.90, providing an accessible and high accuracy non-invasive early stage CVD assessment tool, especially for low and middle-income countries (LMICs).

Phonocardiography (PCG) is used as an adjunct to teach cardiac auscultation and is now a function of PCG-capable stethoscopes (PCS). To evaluate the efficacy of PCG and PCS, the authors investigated the impact of providing PCG data and PCSs on how frequently murmurs, rubs, and gallops (MRGs) were correctly identified by third-year medical students. Following their internal medicine rotation, third-year medical students from the Georgetown University School of Medicine completed a standardized auscultation assessment. Sound files of 10 different MRGs with a corresponding clinical vignette and physical exam location were provided with and without PCG (with interchangeable question stems) as 10 paired questions (20 total questions). Some (32) students also received a PCS to use during their rotation. Discrimination/difficulty indexes, comparative chi-squared, and McNemar test p -values were calculated. The addition of phonocardiograms to audio data was associated with more frequent identification of mitral stenosis, S4, and cardiac friction rub, but less frequent identification of ventricular septal defect, S3, and tricuspid regurgitation. Students with a PCS had a higher frequency of identifying a cardiac friction rub. PCG may improve the identification of low-frequency, usually diastolic, heart sounds but appears to worsen or have little effect on the identification of higher-frequency, often systolic, heart sounds. As digital and phonocardiography-capable stethoscopes become more prevalent, insights regarding their strengths and weaknesses may be incorporated into medical school curricula, bedside rounds (to enhance teaching and diagnosis), and telemedicine/tele-auscultation efforts.

Background: Approximately 50% of children experience a cardiac murmur at some point in their lives; <1% of these murmurs are attributed to congenital heart disease (CHD). Cardiac murmur might be the first clinical sign of a significant CHD in children. Despite careful routine medical examinations at birth, approximately 50% of CHD cases could remain unrecognised., Objective: Cardiovascular symptoms and signs could be specific or non-specific in neonates and children with heart murmurs. Knowledge about red flags in history and physical examinations, and syndromic associations of common CHDs are important. Auscultatory skills to identify systolic, diastolic and continuous murmurs and heart sounds are essential. Differential diagnosis should be formulated based on the location of maximum intensity of murmurs. Younger infants and children with pathological murmurs and red-flag signs should be promptly referred to local paediatric cardiology services for further investigations., Discussion: Significant skill and knowledge are required for the identification of critical murmurs and associated cardiovascular problems. This review provides a simplified comprehensive update on cardiac murmurs and associated conditions in neonates and children.

Objective: To develop a deep learning algorithm to perform multi-class classification of normal pediatric heart sounds, innocent murmurs, and pathologic murmurs., Methods: We prospectively enrolled children under age 18 being evaluated by the Division of Pediatric Cardiology. Parents provided consent for a deidentified recording of their child's heart sounds with a digital stethoscope. Innocent murmurs were validated by a pediatric cardiologist and pathologic murmurs were validated by echocardiogram. To augment our collection of normal heart sounds, we utilized a public database of pediatric heart sound recordings (Oliveira, 2022). We propose two novel approaches for this audio classification task. We train a vision transformer on either Markov transition field or Gramian angular field image representations of the frequency spectrum. We benchmark our results against a ResNet-50 CNN trained on spectrogram images., Results: Our final dataset consisted of 366 normal heart sounds, 175 innocent murmurs, and 216 pathologic murmurs. Innocent murmurs collected include Still's murmur, venous hum, and flow murmurs. Pathologic murmurs included ventricular septal defect, tetralogy of Fallot, aortic regurgitation, aortic stenosis, pulmonary stenosis, mitral regurgitation and stenosis, and tricuspid regurgitation. We find that the Vision Transformer consistently outperforms the ResNet-50 on all three image representations, and that the Gramian angular field is the superior image representation for pediatric heart sounds. We calculated a one-vs-rest multi-class ROC curve for each of the three classes. Our best model achieves an area under the curve (AUC) value of 0.92 ± 0.05, 0.83 ± 0.04, and 0.88 ± 0.04 for identifying normal heart sounds, innocent murmurs, and pathologic murmurs, respectively., Conclusion: We present two novel methods for pediatric heart sound classification, which outperforms the current standard of using a convolutional neural network trained on spectrogram images. To our knowledge, we are the first to demonstrate multi-class classification of pediatric murmurs. Multiclass output affords a more explainable and interpretable model, which can facilitate further model improvement in the downstream model development cycle and enhance clinician trust and therefore adoption., Competing Interests: Declaration of competing interest Research support This research received no external financial or non-financial support. Relationships There are no additional relationships to disclose. Patents and intellectual property Authors George Zhou, Candace Chien, and Yunchan Chen have a patent application pending to Cornell University. Other activities This research received no external funding. There are no additional relationships or activities to disclose., (Copyright © 2024. Published by Elsevier B.V.)

This study was to investigate the value of echocardiographic data in assessing changes in cardiac function before and after transcatheter closure in children and adult patients with patent ductus arteriosus (PDA). In this study, 150 patients with isolated PDA treated by cardiac catheterization and transcatheter closure were selected as the study sample. Real-time color Doppler echocardiography was used both after and after operation. The results showed that the left ventricle returned to normal in 75 patients one day after operation, with an average age of 10.95 ± 3.27 years; the left ventricle did not return to normal in 10 patients 360 days after operation, with an average age of 64.31 ± 7.05 years. Left ventricular end diastolic volume index (LVEDVI) and left ventricular end systolic volume index (LVESVI) of patients decreased significantly one day after operation and remained at 51.95 ± 9.55 mL/m 2 and 20.36 ± 8.11 mL/m -2 , respectively. In summary, echocardiographic data have a high reference value in assessing cardiac function characteristics in children and adult patients with PDA and are worthy of further promotion., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wenhai Wu et al.)

Background: Sedentary lifestyle morbidities are common among children with congenital heart disease (CHD). Understanding the physical activity trajectory from early childhood could enhance timing and effectiveness of interventions., Methods: We recruited 154 children (56% male) at 12 to 47 months of age for this prospective, longitudinal, observational study. Physical activity and sedentary behaviour (7-day accelerometry) and motor skill (Peabody Developmental Motor Scales-2) were assessed every 8 months until 5 years of age and then annually. Mixed-effect repeated measures regression models described outcome trajectories across study assessments., Results: Children had innocent heart murmurs (n = 28), CHD with insignificant hemodynamics not requiring treatment (n = 47), CHD treated by catheterization or surgery without cardiopulmonary bypass (n = 31), or CHD treated surgically with bypass (n = 48). Motor skill was age appropriate (Peabody 49.0 ± 8.4), but participants had lower physical activity (143 ± 41 minutes per day) and higher sedentary time (598 ± 89 minutes per day) than healthy peers, starting at 18 months of age. Movement behaviours were not related to treatment group (P > 0.10), and physical activity was below the recommended 180 minutes per day. Over time, physical activity, sedentary time, and motor skills were primarily related to the baseline measure of each outcome (P < 0.001)., Conclusions: Children with simple or complex CHD or innocent heart murmurs have increased risk for sedentary lifestyles. Their physical activity and sedentary behaviours are established before 2 years of age, persist until school age, and are unrelated to motor skills. These results emphasize the need for interventions targeting the youngest children seen in cardiac clinics, regardless of diagnoses of CHD or innocent murmur., (Copyright © 2021 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

The purpose of this review is to draw attention to the presence and significance of murmurs other than the murmur of aortic regurgitation, in patients with aortic dissection. For that purpose, a literature search was conducted using Pubmed and Googlescholar. The search terms were "dissecting aneurysm of the aorta", "systolic murmurs", "ejection systolic murmurs", "holosystolic" murmurs, "continuous murmurs", and "Austin-Flint" murmur. Murmurs other than the murmur of aortic regurgitation, which were associated with aortic dissection, fell into the categories of systolic murmurs, some of which were holosystolic, and continuous murmurs, the latter attributable to fistulae between the dissecting aneurysm and the left atrium, right atrium, and the pulmonary artery, respectively. Mid-diastolic murmurs were also identified, and these typically occurred in association with both the systolic and the early diastolic murmurs. Among patients with systolic murmurs clinical features which enhanced the pre-test probability of aortic dissection included back pain, stroke, paraplegia, unilateral absence of pulses, interarm differences in blood pressure, hypertension, shock, bicuspid aortic valve, aortic coarctation, Turner's syndrome, and high D-dimer levels, respectively. In the absence of the murmur of aortic regurgitation timely diagnosis of aortic dissection could be expedited by increased attention to parameters which enhance pretest probability of aortic dissection. That logic would apply even if the only murmurs which were elicited were systolic murmurs., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aiming at the problem that the weak features of non-stationary vibration signals are difficult to extract under strong background noise, a multi-layer noise reduction method based on ensemble empirical mode decomposition (EEMD) is proposed. First, the original vibration signal is decomposed by EEMD, and the main intrinsic modal components (IMF) are selected using comprehensive evaluation indicators; the second layer of filtering uses wavelet threshold denoising (WTD) to process the main IMF components. Finally, the virtual noise channel is introduced, and FastICA is used to de-noise and unmix the IMF components processed by the WTD. Next, perform spectral analysis on the separated useful signals to highlight the fault frequency. The feasibility of the proposed method is verified by simulation, and it is applied to the extraction of weak signals of faulty bearings and worn polycrystalline diamond compact bits. The analysis of vibration signals shows that this method can efficiently extract weak fault characteristic information of rotating machinery., Competing Interests: Henan Gaoyuan Maintenance Technology of Highway Co. provided financial support in the form of salary to authors KG, XX, JL, SJ, and NS. This commercial collaboration does not alter the authors’ adherence to all PLOS ONE policies regarding the sharing of data and materials.

Background: Although the clinical importance of heart failure with preserved ejection fraction has been extensively explored, most therapeutic regimens, including nitric oxide (NO) donors, lack therapeutic benefit. Although the clinical characteristics of heart failure with preserved ejection fraction are somewhat heterogeneous, diastolic dysfunction (DD) is one of the most important features. Here we report that neuronal NO synthase (nNOS) induces DD by S-nitrosylation of HDAC2 (histone deacetylase 2)., Methods: Two animal models of DD-SAUNA (SAlty drinking water/Unilateral Nephrectomy/Aldosterone) and mild transverse aortic constriction mice-as well as human heart samples from patients with left ventricular hypertrophy were used. Genetically modified mice that were either nNOS-ablated or HDAC2 S-nitrosylation-resistant were also challenged. N(ω)-propyl-L-arginine, an nNOS selective inhibitor, and dimethyl fumarate, an NRF2 (nuclear factor erythroid 2-related factor 2) inducer, were used. Molecular events were further checked in human left ventricle specimens., Results: SAUNA or mild transverse aortic constriction stress impaired diastolic function and exercise tolerance without overt systolic failure. Among the posttranslational modifications tested, S-nitrosylation was most dramatically increased in both models. Utilizing heart samples from both mice and humans, we observed increases in nNOS expression and NO production. N(ω)-propyl-L-arginine alleviated the development of DD in vivo. Similarly, nNOS knockout mice were resistant to SAUNA stress. nNOS-induced S-nitrosylation of HDAC2 was relayed by transnitrosylation of GAPDH. HDAC2 S-nitrosylation was confirmed in both DD mouse and human left ventricular hypertrophy. S-nitrosylation of HDAC2 took place at C262 and C274. When DD was induced, HDAC2 S-nitrosylation was detected in wild-type mouse, but not in HDAC2 knock-in mouse heart that expressed HDAC2 C262A/C274A. In addition, HDAC2 C262A/C274A mice maintained normal diastolic function under DD stimuli. Gene delivery with adenovirus-associated virus 9 (AAV9)-NRF2, a putative denitrosylase of HDAC2, or pharmacological intervention by dimethyl fumarate successfully induced HDAC2 denitrosylation and mitigated DD in vivo., Conclusions: Our observations are the first to demonstrate a new mechanism underlying DD pathophysiology. Our results provide theoretical and experimental evidence to explain the ineffectiveness of conventional NO enhancement trials for improving DD with heart failure symptoms. More important, our results suggest that reduction of NO or denitrosylation of HDAC2 may provide a new therapeutic platform for the treatment of refractory heart failure with preserved ejection fraction.

Background: The widespread use of cardiac computed tomography (CT) has increased the incidental discovery of fistulas of the coronary artery (CAF). This condition is rare and can affect hemodynamic parameters, but few reports focus on its hemodynamic effects. We investigated the frequency and types of CAF on CT and compared them with those of transthoracic echocardiography (TTE) to evaluate the detectability of CAF and its hemodynamic effects., Materials and Methods: We retrospectively evaluated cardiac CT images of 6789 adult patients who underwent imaging from January 1, 2013 through September 30, 2019 at our institution. We assessed the CT images for the presence of CAF and compared our findings with those obtained by TTE in control cases without CAF., Results: The prevalence of CAF determined with cardiac CT was 0.91%, with the left anterior descending artery (67.7%) as the most common site of origin and the main pulmonary artery (82.3%) as the most common origin of drainage. The incidence of aneurysm accompanying CAF was 48.4%. Color Doppler in TTE demonstrated abnormal flow that would suggest the presence of CAF of only 23.1%. Echocardiographic findings of hemodynamics did not differ significantly between patients with and without CAF nor between elderly and non-elderly patients with CAF., Conclusions: Our study revealed differing prevalence and types of CAF from those reported using coronary angiography and little impact of CAF on hemodynamics. Color Doppler in TTE did not readily depict abnormal flow that might suggest the presence of a fistula, but cardiac CT allowed noninvasive and comprehensive assessment of CAF. Thus, we believe the acquisition of cardiac CT is necessary to establish the cause of continuous murmur that is not identified with TTE., (Copyright © 2020. Published by Elsevier Ltd.)

Introduction: Cardiogenic shock is difficult to diagnose due to diverse presentations, overlap with other shock states (i.e. sepsis), poorly understood pathophysiology, complex and multifactorial causes, and varied hemodynamic parameters. Despite advances in interventions, mortality in patients with cardiogenic shock remains high. Emergency clinicians must be ready to recognize and start appropriate therapy for cardiogenic shock early., Objective: This review will discuss the clinical evaluation and diagnosis of cardiogenic shock in the emergency department with a focus on the emergency clinician., Discussion: The most common cause of cardiogenic shock is a myocardial infarction, though many causes exist. It is classically diagnosed by invasive hemodynamic measures, but the diagnosis can be made in the emergency department by clinical evaluation, diagnostic studies, and ultrasound. Early recognition and stabilization improve morbidity and mortality. This review will focus on identification of cardiogenic shock through clinical examination, laboratory studies, and point-of-care ultrasound., Conclusions: The emergency clinician should use the clinical examination, laboratory studies, electrocardiogram, and point-of-care ultrasound to aid in the identification of cardiogenic shock. Cardiogenic shock has the potential for significant morbidity and mortality if not recognized early., Competing Interests: Declaration of Competing Interest NONE., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Innocent murmurs are common in childhood. Echocardiography may diagnose almost all congenital cardiac abnormalities. Earlier studies have suggested that it may be unnecessary when a clinical diagnosis of an innocent murmur is made by an experienced cardiologist. Yet, echocardiography is commonly performed despite such a diagnosis. Is that justifiable?, Methods: Patients referred to a paediatric cardiologist for evaluation of a murmur were assessed. If an innocent murmur was clinically diagnosed, an echocardiogram and an electrocardiogram were ordered when requested. The cardiologist completed a questionnaire documenting the reasons for the investigations and his degree of confidence in the clinical diagnosis. The parents and patients were informed of the diagnosis and the results of the investigations., Results: In almost all 62 cases whose murmurs were clinically considered to be innocent, the referring doctor expected an echocardiogram to be performed. Following echocardiography, one patient was found to have a small muscular ventricular septal defect. On review, the murmur was consistent with that diagnosis. Three (3) others had abnormal echocardiograms namely congenitally corrected transposition of great arteries, partial anomalous right upper lobe pulmonary vein, and left ventricular non-compaction. All on review were still considered clinically to have innocent murmurs., Conclusions: Despite the competency of the cardiologist, echocardiography diagnosed important but relatively uncommon cardiac abnormalities with prognostic implications that would have been missed if only the clinical examination was performed. Over and above the referring doctor's expectations for an echocardiogram to be performed is the need for the cardiologist to provide a complete and definitive diagnosis., (Copyright © 2019 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Successful management of a pregnant patient with complex congenital heart disease is a challenge for anesthesiologists, requiring thorough knowledge of the impact of pregnancy on the cardiac lesion. Hearing and speech impaired patients pose a barrier to effective communication between the patient and the doctors, thus increasing the anxiety and risk of complications. Here, we present a case of a hearing and speech impaired woman with the rare and dangerous Eisenmenger's syndrome, presenting for an emergency cesarean section (CS).

Pimobendan has gained enormous importance in the treatment of mitral valve disease in dogs. The current consensus statement of the American College of Veterinary Internal Medicine (ACVIM) recommends a treatment for dogs with symptomatic disease and dogs with asymptomatic disease with radiographic and echocardiographic signs of cardiomegaly. To investigate whether these dogs also benefit from a therapy with pimobendan, 21 dogs with mitral valve disease ACVIM B1 underwent a standardized submaximal exercise test on a treadmill. In this double-blinded and randomized study, the animals were divided into two groups, one receiving pimobendan and the other a placebo. At the first visit and at every follow-up appointment (at days 90 and 180), heart rate during the complete exercise test and lactate before and after running were measured. In addition to this, a questionnaire was completed by the dogs' owners and all dogs were given an echocardiographic examination to detect any changes and to observe if the disease had progressed. Due to the diagnosis of leishmaniosis, one dog in the pimobendan group was retrospectively removed from the study so that 20 dogs were included for statistical analysis. No differences were observed at any time between the pimobendan-group and the placebo-group regarding heart rate. At day 180, the increase in lactate after exercise was significantly lower than in the placebo-group. The increase in the pimobendan-group at day 180 was lower than at day 90. Most of the dog owners from the pimobendan-group declared that their dogs were more active at day 90 (6/10) and at day 180 (8/10), while most dog owners from the placebo-group observed no changes regarding activity at day 90 (8/10) and day 180 (6/10). It can be concluded that the results of this study indicate that some dogs with mitral valve disease ACVIM B1 might benefit from a therapy with pimobendan., Competing Interests: The authors have declared that no competing interests exist.

Heart sound and its recorded signal which is known as phonocardiograph (PCG) are one of the most important biosignals that can be used to diagnose cardiac diseases alongside electrocardiogram (ECG). Over the past few years, the use of PCG signals has become more widespread and researchers pay their attention to it and aim to provide an automated heart sound analysis and classification system that supports medical professionals in their decision. In this paper, a new method for heart sound features extraction for the classification of non-segmented signals using instantaneous frequency was proposed. The method has two major phases: the first phase is to estimate the instantaneous frequency of the recorded signal; the second phase is to extract a set of eleven features from the estimated instantaneous frequency. The method was tested into two different datasets, one for binary classification (Normal and Abnormal) and the other for multi-classification (Five Classes) to ensure the robustness of the extracted features. The overall accuracy, sensitivity, specificity, and precision for binary classification and multi-classification were all above 95% using both random forest and KNN classifiers.

The problem addressed in this work is the detection of a heart murmur and the classification of the associated cardiovascular disorder based on the heart sound signal. For this purpose, a dataset of Phonocardiogram (PCG) signals is acquired using baseline conditions. The dataset is acquired from 283 volunteers using Littman 3200 electronic stethoscope for a normal and four different types of heart murmurs. The samples are labelled and validated through echocardiography test of each participating volunteer. For feature extraction, normalized average Shannon energy with time-domain characteristics of heart sound signal is exploited to segment the PCG signal into its components. To improve the quality of the features, in contrast to the previous methods, all systole and diastole intervals are utilized to extract 50 Mel-Frequency Cepstrum Coefficients (MFCC) based features. Then, the iterative backward elimination method is used to identify and remove the redundant features to reduce the complexity in order to conceive a computationally tractable system. An MFCC feature vector of dimension 26 is selected for training seven different types of Support Vector Machine (SVM) and K-Nearest Neighbors (KNN) based classifiers for detection and classification of cardiovascular disorders. Fivefold cross-validation and 20% data holdout validation schemes are used for testing the classifiers. Classification accuracy of 92.6% is achieved using selected features and medium Gaussian SVM classifier. The learning curves show a good bias-variance trade-off indicating a well-fitted and generalized model for making future predictions.

Innocent cardiac murmurs are common findings in Cairn terrier puppies during their first veterinary health check. The age when these murmurs spontaneously disappear is unreported. The purpose of this study was to establish the age when presumably innocent cardiac murmurs disappear in a population of clinically healthy Cairn terrier puppies. Over a period of 9 months, 227 clinically healthy Cairn terrier puppies (median age, 53 days; range, 45-76 days) underwent auscultation by a veterinary cardiology specialist, who identified 82 puppies with a presumably innocent cardiac murmur. Owners of 20 puppies volunteered to return to the clinic for serial rechecks. Owners of three puppies returned only once, therefore these puppies were censored. Hence this longitudinal observational study followed 17 puppies with monthly cardiac auscultation until the disappearance of their murmurs. The median age of the 20 puppies when the murmur was last audible was 65 days (range 52-285 days). The median age of the 17 puppies when the murmur was no longer audible was 87 days (range 71-347 days; 95% confidence interval 63-111 days). Four of the 17 puppies had a murmur after 3 months of age and two of them had a murmur beyond 6 months of age. The oldest puppy to have an audible murmur was 9.5 months old; this murmur was not audible at 11.5 months of age. In most Cairn terrier puppies in this population, the presumably innocent murmur resolved spontaneously by 3 months of age., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Arrhythmias detected on prepurchase examination should be confirmed with an ECG. Exercising ECG determines if the arrhythmia is overdriven during exercise or is a safety concern. An echocardiogram is needed in all horses with a grade 3/6 or louder mid to late systolic, holosystolic, or pansystolic murmur or any holodiastolic decrescendo murmur to identify the cardiac abnormality and its hemodynamic impact. Most horses with arrhythmias and murmurs have a normal performance career and life expectancy and are insurable. Risks for sudden death and congestive heart failure associated with the common murmurs and arrhythmias are identified, because these horses cannot be insured., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: There are two major challenges in automated heart sound analysis: segmentation and classification. An efficient segmentation is capable of providing valuable diagnostic information of patients. In addition, it is crucial for some feature-extraction based classification methods. Therefore, the segmentation of heart sound is of significant value., Methods: This paper presents an automatic heart sound segmentation method that combines the time-domain analysis, frequency-domain analysis and time-frequency-domain analysis. Employing this method, the boundaries of heart sound components are first located, and the components are then recognized. Finally, the heart sounds are divided into several segments on the basis of the results of boundary localization and component identification., Results: In order to evaluate the performance of the proposed method, quantitative experiments are performed on an authoritative heart sound database. The experimental results show that the boundary localization has a sensitivity (Se) of 100%, a positive predictive value (PPV) of 99.3% and an accuracy (Acc) of 99.93%. Moreover, the Se, PPV and Acc of component identification reach 98.63, 99.86 and 98.49%, respectively., Conclusion: The proposed method shows reliable performance on the segmentation of heart sounds. Compared with previous works, this method can be applied to not only normal heart sounds, but also the sounds with S3, S4 and murmurs, thus greatly increasing the applied range.

Auscultation of heart dispenses identification of the cardiac valves. An electronic stethoscope is used for the acquisition of heart murmurs that is further classified into normal or abnormal murmurs. The process of heart sound segmentation involves discrete wavelet transform to obtain individual components of the heart signal and its separation into systole and diastole intervals. This research presents a novel scheme to develop a semi-automatic cardiac valve disorder diagnosis system. Accordingly, features are extracted using wavelet transform and spectral analysis of input signals. The proposed classification scheme is the fusion of adaptive-neuro fuzzy inference system (ANFIS) and HMM. Both classifiers are trained using the extracted features to correctly identify normal and abnormal heart murmurs. Experimental results thus achieved exhibit that proposed system furnishes promising classification accuracy with excellent specificity and sensitivity. However, the proposed system has fewer classification errors, fewer computations, and lower dimensional feature set to build an intelligent system for detection and classification of heart murmurs., (© 2018 Wiley Periodicals, Inc.)

A diastolic paradoxical jet flow, often seen in patients with hypertrophic cardiomyopathy, is a unique flow from the apex toward the base of the left ventricle during isovolumic relaxation. To date, this phenomenon appears to have been noninvasively detected only on echocardiograms. We report the case of a 43-year-old man with hypertrophic cardiomyopathy and a diastolic paradoxical jet flow, in whom cardiac auscultation revealed a soft S 4 , a systolic ejection murmur, and a low-pitched early diastolic murmur immediately after S 2 at the apex. On comparing his echocardiographic findings with those on phonocardiograms and apexcardiograms, we confirmed that the unusual murmur coincided with the diastolic jet flow. To our knowledge, this is the first case in which heart murmurs associated with a diastolic paradoxical jet flow have been clearly described. Because these flows can increase the risk of adverse outcomes, detecting any associated murmurs by methods other than echocardiography is worthwhile, even in the era of advanced imaging techniques.

Importance: Hutchinson-Gilford progeria syndrome (HGPS) is an ultrarare disorder associated with premature death due to cardiovascular events during the second decade of life. However, because of its rarity (107 identified living patients), the natural history of cardiac disease remains uncharacterized. Therefore, meaningful cardiac end points for clinical trials have been difficult to establish., Objective: To examine the course of appearance of cardiac abnormalities in patients with HGPS to identify meaningful cardiac end points for use in future clinical trials., Design, Setting, and Participants: In this prospective, cross-sectional, observational study, 27 consecutive patients with clinically and genetically confirmed classic HGPS were evaluated at a single center for 1 visit from July 1, 2014, through February 29, 2016, before initiation of treatment., Exposure: Classic HGPS., Main Outcomes and Measures: Echocardiography was used to assess ventricular and valve function using standard techniques. Diastolic left ventricular (LV) function was assessed using tissue Doppler imaging. Previously published normative data were used to adjust findings to age and body size., Results: This study included 27 patients (median age, 5.6 years; age range, 2-17 years; 15 [56%] male). Among echocardiographic indicators, LV diastolic dysfunction, defined as a tissue Doppler septal or lateral early velocity z score less than -2, was the most prevalent abnormality, seen in 16 patients (59%). Diastolic dysfunction was seen in all age groups, and its prevalence increased with age, mirroring findings seen during normal aging. Indicators of LV diastolic function were more abnormal in older patients. The z scores for lateral and septal early velocities were lower (r = -0.77, P < .001; and r = -0.66, P < .001, respectively), whereas those for the ratio of early mitral inflow velocity to early diastolic tissue Doppler myocardial velocity were higher (r = 0.80, P < .001; and r = 0.72, P < .001, respectively) in older patients. Other echocardiographic findings, including LV hypertrophy, LV systolic dysfunction, and valve disease, were less prevalent in the first decade and were seen more frequently in the second decade., Conclusions and Relevance: In this largest-to-date cohort of patients with HGPS, LV diastolic dysfunction was the most prevalent echocardiographic abnormality and its prevalence increased with aging. Echocardiographic indicators of LV diastolic function may be useful end points in future clinical trials in this patient population.

Objective: To investigate the association between maternal vascular murmurs (MVMs) and fetal growth restriction (defined as small-for-gestational-age [SGA] fetus) and abnormal Doppler pulsatility index (PI) of the uterine and/or umbilical arteries., Methods: A cross-sectional study of women aged 18 years or older with a singleton pregnancy at 28-34 weeks was conducted at Regional Hospital Viborg, Denmark, between May 1 and August 1, 2013. Ultrasound fetal biometry was performed and the Doppler PI of the umbilical and uterine arteries was determined. An estimated fetal weight (EFW) at or below the 10th percentile was defined as SGA. Microphone recordings from the lower abdomen were divided into heart valve sounds and MVMs., Results: The final analysis included 63 participants, with 25 classified as SGA and 38 as non-SGA. The mean pregnancy duration was 32.4 ± 1.4 weeks. In total, 17 participants had MVMs. There was a clear association between MVMs and a composite of SGA and an abnormal PI of the uterine and/or the umbilical artery (P<0.001), but not between MVMs and SGA only (P=0.154)., Conclusion: Maternal vascular murmurs are significantly associated with fetal growth restriction, but not with SGA per se., (© 2017 International Federation of Gynecology and Obstetrics.)

An asymptomatic 45-year-old man was referred to our hospital for detailed evaluation of a systolic ejection murmur. The intensity of the murmur increased on deep expiration and decreased on deep inspiration, showing so-called reversed Rivero-Carvallo's sign. Using cardiac magnetic resonance imaging, we demonstrated a characteristic respiratory-induced change in peak flow velocity in the right ventricular outflow tract, which was the basic mechanism of the reversed Rivero-Carvallo's sign in a case with straight back syndrome. Concomitant anatomical changes in the entire heart in relation to the thoracic cage were also clarified., (© 2017, Wiley Periodicals, Inc.)

Objective: To determine the appropriateness and yield of transthoracic echocardiograms (TTE) for murmur evaluation based on the pediatric Appropriate Use Criteria (AUC) and study the influence of patient age and physician experience on TTE appropriateness, yield, and ordering frequency., Design: Retrospective review of medical records of patients referred to our practice for murmur evaluation from April to September 2014. Data collected included indication for TTE, patient age, physician experience since fellowship, TTE findings and exit diagnosis. Appropriateness was assigned based on the AUC document., Setting: Pediatric cardiology clinics affiliated with a large pediatric cardiology practice., Patients: One thousand seven hundred one consecutive patients (≤ 18 years) referred to our practice for murmur evaluation., Interventions: Not applicable OUTCOME MEASURES: The primary outcome was appropriateness of TTE orders. The secondary outcomes were the yield of abnormal TTE findings and the influence of patient age and physician experience on appropriateness, yield, and frequency of ordering TTEs., Results: Of the 1701 patients referred for a murmur, 526 (30.9%) had a TTE [441/526 (83.8%) Appropriate; 85/526 (16.2%) Rarely Appropriate]. Abnormal findings were present in 130/441 rated Appropriate and none rated Rarely Appropriate. Infants <3 months had the highest rate of TTEs rated Appropriate and the highest yield of abnormal findings. Physicians with >20 years of experience not only had the lowest TTE ordering rate but also the lowest appropriateness rate with no difference in the yield of abnormal findings., Conclusions: Most TTEs ordered for murmur were for indications rated Appropriate. Abnormal findings were present in one-fourth and only those rated Appropriate. Patient age and physician experience can significantly influence TTE utilization. This information is helpful in designing quality initiatives to optimize TTE utilization for murmur evaluation., (© 2016 Wiley Periodicals, Inc.)

Physiological mechano-acoustic signals, often with frequencies and intensities that are beyond those associated with the audible range, provide information of great clinical utility. Stethoscopes and digital accelerometers in conventional packages can capture some relevant data, but neither is suitable for use in a continuous, wearable mode, and both have shortcomings associated with mechanical transduction of signals through the skin. We report a soft, conformal class of device configured specifically for mechano-acoustic recording from the skin, capable of being used on nearly any part of the body, in forms that maximize detectable signals and allow for multimodal operation, such as electrophysiological recording. Experimental and computational studies highlight the key roles of low effective modulus and low areal mass density for effective operation in this type of measurement mode on the skin. Demonstrations involving seismocardiography and heart murmur detection in a series of cardiac patients illustrate utility in advanced clinical diagnostics. Monitoring of pump thrombosis in ventricular assist devices provides an example in characterization of mechanical implants. Speech recognition and human-machine interfaces represent additional demonstrated applications. These and other possibilities suggest broad-ranging uses for soft, skin-integrated digital technologies that can capture human body acoustics.

Innocent heart murmurs are quite common in children and adolescents. These murmurs are physiologic in nature and are not associated with any structural heart disease. Not only does the idea of having a child with a murmur bring unnecessary unrest to families, but the child also often goes through numerous tests that could be avoided. It is critical to obtain a detailed history and perform a thorough physical examination to diagnose these innocent murmurs. This article reviews the different types of innocent murmurs, their characteristics, how they can be differentiated on the physical examination, and most importantly, how they can be differentiated from pathologic murmurs, which require referral to a pediatric cardiologist and additional testing. [Pediatr Ann. 2016;45(8):e306-e309.]., (Copyright 2016, SLACK Incorporated.)

Background: Echocardiographic assessment of diastolic function is challenging in cats, partially because of transmitral flow pattern fusion associated with high heart rates. With heart rate (HR) reduction, transmitral flow waveforms separate, allowing identification of diastolic dysfunction. Timolol, an ophthalmic, nonselective beta-blocker used in glaucoma is safe and transiently decreases HR in clinical trials., Hypothesis: Administration of timolol ophthalmic solution decreases HR and facilitates echocardiographic assessment of diastolic function in cats without inducing clinically relevant adverse effects., Animals: Twenty-five apparently healthy cats., Methods: Electrocardiograms and echocardiograms including transmitral flow patterns were evaluated before and 20 minutes after ocular administration of 1 drop of timolol 0.5% solution. Twenty cats underwent treatment with timolol, and 5 different cats served as untreated controls to evaluate the effects of acclimation to the hospital environment on HR., Results: Acclimation to the hospital had no effect on HR in control cats. After timolol administration, a significant median HR reduction of 25 bpm was observed (P < .0001). Timolol had no effect on E/A ratio in cats without E/A fusion (7/20, P = .44). Of the 13 cats with E and A waves that were fused before timolol application, separation of these waves was identified in 8 cats (62%) after timolol treatment. No bradyarrhythmias were noted after timolol administration, but 2 cats had first-degree atrioventricular block. Timolol resulted in resolution of dynamic outflow tract obstruction in 6 of 6 cats., Conclusions and Clinical Importance: Ocular administration of timolol safely decreases HR in cats and could facilitate assessment of diastolic function., (Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Background: A phonocardiogram (PCG) signal can be recorded for long-term heart monitoring. A huge amount of data is produced if the time of a recording is as long as days or weeks. It is necessary to compress the PCG signal to reduce storage space in a record and play system. In another situation, the PCG signal is transmitted to a remote health care center for automatic analysis in telemedicine. Compression of the PCG signal in that situation is necessary as a means for reducing the amount of data to be transmitted. Since heart beats are of a cyclical nature, compression can make use of the similarities in adjacent cycles by eliminating repetitive elements as redundant. This study proposes a new compression method that takes advantage of these repetitions., Methods: Data compression proceeds in two stages, a training stage followed by the compression as such. In the training stage, a section of the PCG signal is selected and its sounds and murmurs (if any) decomposed into time-frequency components. Basic components are extracted from these by clustering and collected to form a dictionary that allows the generative reconstruction and retrieval of any heart sound or murmur. In the compression stage, the heart sounds and murmurs are reconstructed from the basic components stored in the dictionary. Compression is made possible because only the times of occurrence and the dictionary indices of the basic components need to be stored, which greatly reduces the number of bits required to represent heart sounds and murmurs. The residual that cannot be reconstructed in this manner appears as a random sequence and is further compressed by vector quantization. What we propose are quick search parameters for this vector quantization., Results: For normal PCG signals the compression ratio ranges from 20 to 149, for signals with median murmurs it ranges from 14 to 35, and for those with heavy murmurs, from 8 to 20, subject to a degree of distortion of ~5% (in percent root-mean-square difference) and a sampling frequency of 4kHz., Discussion: We discuss the selection of the training signal and the contribution of vector quantization. Performance comparisons between the method proposed in this study and existing methods are conducted by computer simulations., Conclusions: When recording and compressing cyclical sounds, any repetitive components can be removed as redundant. The redundancies in the residual can be reduced by vector quantization. The method proposed in this study achieves a better performance than existing methods., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Past decades witnessed the expansion of linear signal processing methods in numerous biomedical applications. However, the nonlinear behavior of biomedical signals revived the interest in nonlinear signal processing methods such as higher-order statistics, in particular higher-order cumulants (HOC). In this paper, HOC are utilized toward heart sound classification. Heart sounds are presented by wavelet packet decomposition trees. Information measures are then defined based on HOC of wavelet packet coefficients, and three basis selection methods are proposed to prune the trees and preserve the most informative nodes for feature extraction. In addition, an approach is introduced to reduce the dimensionality of the search space from the whole wavelet packet tree to a trapezoidal sub-tree of it. This approach can be recommended for signals with a short frequency range. HOC features are extracted from the coefficients of selected nodes and fed into support vector machine classifier. Experimental data is a set of 59 heart sounds from different categories: normal heart sounds, mitral regurgitation, aortic stenosis, and aortic regurgitation. The promising results achieved indicate the capabilities of HOC of wavelet packet coefficients to capture nonlinear characteristics of the heart sounds to be used for basis selection.

This paper presents a novel method for discrimination between innocent and pathological murmurs using the growing time support vector machine (GTSVM). The proposed method is tailored for characterizing innocent murmurs (IM) by putting more emphasis on the early parts of the signal as IMs are often heard in early systolic phase. Individuals with mild to severe aortic stenosis (AS) and IM are the two groups subjected to analysis, taking the normal individuals with no murmur (NM) as the control group. The AS is selected due to the similarity of its murmur to IM, particularly in mild cases. To investigate the effect of the growing time windows, the performance of the GTSVM is compared to that of a conventional support vector machine (SVM), using repeated random sub-sampling method. The mean value of the classification rate/sensitivity is found to be 88%/86% for the GTSVM and 84%/83% for the SVM. The statistical evaluations show that the GTSVM significantly improves performance of the classification as compared to the SVM., (Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.)

Cardiac auscultation permits to distinguish between the innocent heart murmurs and pathologic murmurs; characteristics of pathologic murmurs include a holosystolic or diastolic murmur, maximal murmur intensity at the upper left sternal border and increased intensity when the patient stands. Murmurs should be described by their timing in the cardiac cycle, intensity, shape, pitch, location, radiation, and response to dynamic maneuvers. When the medical history and physical examination support the diagnosis of innocent heart murmur, neither further investigation nor referal is indicated. On the contrary, echocardiography is recommended for patients with any other abnormal physical examination findings that increase the likelihood of structural heart disease. In this review we discuss the definition and classification of murmurs, how to evaluate it.

The first-time appearance of a murmur in an adolescent can create a substantial amount of anxiety in the parents and the teenager. The appropriate evaluation and diagnosis is very important in decision-making regarding sports participation in this population. Accurate identification of the innocent murmurs can obviate the need for echocardiography. Identification of a pathologic murmur may reduce morbidity and, possibly, mortality in critical lesions such as hypertrophic cardiomyopathy. This article discusses the physiology and characteristics of different murmurs, and outlines an approach to cardiac murmurs in adolescents., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In this paper, an approach on analysis of the pathologic cardiac murmurs for congenital heart defects was proposed based on the wavelet packet (WP) technique. Considering the difference of the energy intensity distributions for the innocent and pathologic murmurs in frequency domain, the WP decomposition was introduced and the WP energies at each frequency band were calculated and compared. Based on the analysis of a large amount of clinic heart sound data, the murmurs energy distributions were divided into five frequency bands, and the relative evaluation indexes for cardiac murmurs (ICM) were proposed for analysis of the pathologic murmurs. Finally, the threshold values between the innocent and pathologic cardiac murmurs were determined based on the statistical results of the normal heart sounds. The analysis results validate the proposed evaluation indexes and the corresponding thresholds.

We present the case of a young man with severe eccentric aortic regurgitation, obstructing mitral inflow and provoking an audible Austin Flint murmur at clinical examination. Two-dimensional color Doppler echocardiography depicts the remarkable mechanical interaction between aortic regurgitant jet and anterior mitral leaflet opening. Three-dimensional transesophageal echocardiography aids in understanding the geometric and hemodynamic consequences of the regurgitant jet and in the genesis of the Austin Flint murmur. This case accentuates the incremental value of three-dimensional echocardiography when evaluating valvular pathology, and offers more insight in the interaction between aortic regurgitant flow and mitral leaflet dynamics.

Congenital heart defects can be classified as those characterized by a left to right shunt, a right to left shunt, obstruction to flow from the heart, or abnormalcies of myocardial contraction and relaxation. Left to right shunts include atrial and ventricular septal defects, and patent ductus arteriosus. Right to left shunts include transposition of the great arteries, tetralogy of Fallot, tricuspid atresia among others. These defects result in cyanosis. Lesions causing obstruction to blood flow from the heart include aortic and pulmonary valve stenosis and coarctation of the aorta. Disorders of myocardial contraction and relation include hypertrophic, dilated, and restrictive cardiomyopathies. In addition, the author will discuss innocent heart murmur and Kawasaki’s disease.

We present a novel, low complexity method for the detection of the first and second of heart sounds (S1 and S2, respectively) and the periods of systole and diastole without using an electrocardiogram reference. The algorithm uses a technique called empirical mode decomposition to produce intensity envelopes of the main heart sounds in the time domain. The performance of the algorithm was evaluated using 14,000 cardiac periods from 100 normal and abnormal digital phonocardiographic recordings. The sensitivity of the detection method was 88.3% for both S1 and S2, and the precision (positive predictive value) was 95.8% for both S1 and S2.

Heart sounds and murmurs provide crucial diagnosis information for several heart diseases such as natural or prosthetic valve dysfunction and heart failure. Many pathological conditions of the cardiovascular system cause murmurs and aberrations in heart sounds. Phonocardiography provides the clinician with a complementary tool to record the heart sounds heard during auscultation. The advancement of intra-cardiac phonocardiography, combined with modern digital processing techniques, has strongly renewed researchers' interest in studying heart sounds and murmurs. This paper presents an algorithm for the detection of heart sounds (the first and second sounds, S1 and S2) and heart murmurs. The segmentation algorithm is based on the detection of the envelope of the phonocardiogram signal by the Hilbert transform technique, which is used to extract a smooth envelogram which enable one to apply the tests necessary for temporal localization of heart sounds and heart murmurs.

In the present work, a modularized approach to computer-aided auscultation based on the traditional cardiac auscultation of murmur is proposed. Under such an approach, the present paper concerns the task of evaluating murmur acoustic quality character. The murmurs were analyzed in their time-series representation, frequency representation as well as time-frequency representation, allowing extraction of interpretable features based on their signal structural and spectral characters. The features were evaluated using scatter plots, receiver operating characteristic curves (ROC), and numerical experiments using a KNN classifier. The possible physiological and hemodynamical associations with the feature set are made. The implication and advantage of the modular approach are discussed., (Copyright © 2013 Elsevier Ltd. All rights reserved.)