-
Sensors (Basel, Switzerland) Jun 2024The phonocardiogram (PCG) can be used as an affordable way to monitor heart conditions. This study proposes the training and testing of several classifiers based on SVMs...
The phonocardiogram (PCG) can be used as an affordable way to monitor heart conditions. This study proposes the training and testing of several classifiers based on SVMs (support vector machines), k-NN (k-Nearest Neighbor), and NNs (neural networks) to perform binary ("Normal"/"Pathologic") and multiclass ("Normal", "CAD" (coronary artery disease), "MVP" (mitral valve prolapse), and "Benign" (benign murmurs)) classification of PCG signals, without heart sound segmentation algorithms. Two datasets of 482 and 826 PCG signals from the Physionet/CinC 2016 dataset are used to train the binary and multiclass classifiers, respectively. Each PCG signal is pre-processed, with spike removal, denoising, filtering, and normalization; afterward, it is divided into 5 s frames with a 1 s shift. Subsequently, a feature set is extracted from each frame to train and test the binary and multiclass classifiers. Concerning the binary classification, the trained classifiers yielded accuracies ranging from 92.4 to 98.7% on the test set, with memory occupations from 92.7 kB to 11.1 MB. Regarding the multiclass classification, the trained classifiers achieved accuracies spanning from 95.3 to 98.6% on the test set, occupying a memory portion from 233 kB to 14.1 MB. The NNs trained and tested in this work offer the best trade-off between performance and memory occupation, whereas the trained k-NN models obtained the best performance at the cost of large memory occupation (up to 14.1 MB). The classifiers' performance slightly depends on the signal quality, since a denoising step is performed during pre-processing. To this end, the signal-to-noise ratio (SNR) was acquired before and after the denoising, indicating an improvement between 15 and 30 dB. The trained and tested models occupy relatively little memory, enabling their implementation in resource-limited systems.
Topics: Humans; Phonocardiography; Machine Learning; Signal Processing, Computer-Assisted; Algorithms; Neural Networks, Computer; Wearable Electronic Devices; Support Vector Machine
PubMed: 38931636
DOI: 10.3390/s24123853 -
Animals : An Open Access Journal From... Jun 2024Heart murmurs in puppies can be innocent or pathologic; the latter is almost always related to a congenital heart disease. Differentiating between these murmurs can be...
BACKGROUND
Heart murmurs in puppies can be innocent or pathologic; the latter is almost always related to a congenital heart disease. Differentiating between these murmurs can be challenging for practicing veterinarians, but this differentiation is essential to ensure the best prognosis for puppies having a congenital heart disease. Our study aimed to reveal how veterinarians manage puppies with a heart murmur.
METHODS
A web-based questionnaire was sent to Dutch and Belgian veterinary practices.
RESULTS
Data from 452 respondents were analyzed. Though 88% of the respondents find detecting a heart murmur easy, only 9% find differentiating innocent murmurs from pathologic murmurs in puppies easy. Of the respondents, only 80% recommend immediate additional examination when detecting a loud heart murmur during the first veterinary health check at 6 weeks of age. Most of the respondents are aware that normal growth and the absence of clinical signs do not exclude severe congenital heart disease. Of the respondents, 31% were uncertain whether early surgical intervention could lead to improved outcomes.
CONCLUSIONS
Veterinarians are aware of the importance of echocardiography for puppies with a loud heart murmur, and recognize their limitations when differentiating an innocent from a pathological heart murmur in a puppy.
PubMed: 38929440
DOI: 10.3390/ani14121821 -
Frontiers in Pediatrics 2024Atrial septal defect (ASD) is a congenital heart disease that often presents without symptoms or murmurs. If left untreated, children with ASD can develop comorbidities...
BACKGROUND
Atrial septal defect (ASD) is a congenital heart disease that often presents without symptoms or murmurs. If left untreated, children with ASD can develop comorbidities in adulthood. In Japan, school electrocardiography (ECG) screening has been implemented for all 1st, 7th, and 10th graders. However, the impact of this program in detecting children with ASD is unknown.
METHODS
This is a retrospective study that analyzed consecutive patients with ASD who underwent catheterization for surgical or catheter closure at ≤18 years of age during 2009-2019 at a tertiary referral center in Japan.
RESULTS
Of the overall 116 patients with ASD (median age: 3.0 years of age at diagnosis and 8.9 years at catheterization), 43 (37%) were prompted by the ECG screening (Screening group), while the remaining 73 (63%) were by other findings (Non-screening group). Of the 49 patients diagnosed at ≥6 years of age, 43 (88%) were prompted by the ECG screening, with the 3 corresponding peaks of the number of patients at diagnosis. Compared with the non-screening group, the screening group exhibited similar levels of hemodynamic parameters but had a lower proportion of audible heart murmur, which were mainly prompted by the health care and health checkups in infancy or preschool period. Patients positive for a composite parameter (rsR' type of iRBBB, inverted T in V4, or ST depression in the aVF lead) accounted for 79% of the screening group at catheterization, each of which was correlated with hemodynamic parameters in the overall patients.
CONCLUSIONS
The present study shows that school ECG screening detects otherwise unrecognized ASD, which prompted the diagnosis of the majority of patients at school age and >one-third of overall patients in Japan. These findings suggest that ECG screening program could be an effective strategy for detecting hemodynamically significant ASD in students, who are asymptomatic and murmurless.
PubMed: 38887565
DOI: 10.3389/fped.2024.1396853 -
International Journal of Cardiology Sep 2024Transthoracic echocardiography (TTE) is routinely required during pre-participation screening in the presence of symptoms, family history of sudden cardiac death or... (Review)
Review
Transthoracic echocardiography (TTE) is routinely required during pre-participation screening in the presence of symptoms, family history of sudden cardiac death or cardiomyopathies <40-year-old, murmurs, abnormal ECG findings or in the follow-up of athletes with a history of cardiovascular disease (CVD). TTE is a cost-effective first-line imaging modality to evaluate the cardiac remodeling due to long-term, intense training, previously known as the athlete's heart, and to rule out the presence of conditions at risk of sudden cardiac death, including cardiomyopathies, coronary artery anomalies, congenital, aortic and heart valve diseases. Moreover, TTE is useful for distinguishing physiological cardiac adaptations during intense exercise from pathological behavior due to an underlying CVD. In this expert opinion statement endorsed by the Italian Society of Sports Cardiology, we discussed common clinical scenarios where a TTE is required and conditions falling in the grey zone between the athlete's heart and underlying cardiomyopathies or other CVD. In addition, we propose a minimum dataset that should be included in the report for the most common indications of TTE in sports cardiology clinical practice.
Topics: Humans; Echocardiography; Sports Medicine; Italy; Societies, Medical; Cardiology; Death, Sudden, Cardiac; Athletes; Expert Testimony; Sports; Cardiovascular Diseases
PubMed: 38852859
DOI: 10.1016/j.ijcard.2024.132230 -
Postgraduate Medicine May 2024This study aimed to assess physicians' approach to cardiac murmurs and their level of knowledge about this sign, which is a crucial finding in childhood cardiac...
OBJECTIVE
This study aimed to assess physicians' approach to cardiac murmurs and their level of knowledge about this sign, which is a crucial finding in childhood cardiac anomalies.
METHODS
The study intended to include all family physicians in the Adıyaman province of Turkey, but ultimately 150 out of 210 physicians participated and was completed with a percentage response rate of 71%. Participants were asked about their approach to cardiac murmurs, answered knowledge questions, and completed a questionnaire on demographic characteristics. Subsequently, eight heart sounds were played, and participants were asked to identify the nature of each sound.
RESULTS
Family medicine specialists (all scores were < 0.001) and physicians who completed a pediatric internship lasting over a month (knowledge score = 0.012, behavioral score = 0.021, recording score = 0.01) demonstrated significantly higher knowledge, approach, and recording scores. Age and years in the profession showed a negative correlation with recording scores.
CONCLUSIONS
The study highlights the significant impact of various factors such as gender, specialization, internship duration, experience, and theoretical knowledge on the ability to recognize and approach cardiac murmurs. These findings underscore the importance of incorporating these factors into medical education and development programs, especially those aimed at improving cardiac examination skills.
Topics: Humans; Male; Female; Heart Murmurs; Clinical Competence; Turkey; Adult; Surveys and Questionnaires; Child; Middle Aged; Health Knowledge, Attitudes, Practice
PubMed: 38805321
DOI: 10.1080/00325481.2024.2360387 -
Journal of Echocardiography May 2024An 18-month-old boy presented with recurrent episodes of irritability and documented fast heart rate suggestive of supraventricular tachycardia. Cardiovascular...
An 18-month-old boy presented with recurrent episodes of irritability and documented fast heart rate suggestive of supraventricular tachycardia. Cardiovascular examination revealed significant cardiomegaly, normal heart sounds and no murmurs. The differential diagnosis of marked right atrial dilatation and management principles of idiopathic dilatation of the right atrium are described.
PubMed: 38789653
DOI: 10.1007/s12574-024-00651-1 -
Animals : An Open Access Journal From... Apr 2024Auscultation of heart sounds is an important veterinary skill requiring an understanding of anatomy, physiology, pathophysiology and pattern recognition. This...
Auscultation of heart sounds is an important veterinary skill requiring an understanding of anatomy, physiology, pathophysiology and pattern recognition. This cross-sectional study was developed to evaluate a targeted, audio-visual training resource for veterinary students to improve their understanding and auscultation of common heart conditions in horses. Fourth- and fifth-year 2021 and 2022 Bachelor of Veterinary Science students at the University of Queensland (UQ) were provided the learning resource and surveyed via online pre- and post-intervention surveys. Results were quantitatively analyzed using descriptive statistics and Mann-Whitney U tests. Open-ended survey questions were qualitatively analyzed by thematic analysis and Leximancer™ Version 4 program software analysis. Over the two-year period, 231 fourth-year and 222 fifth-year veterinary students had access to the resource; 89 completed the pre-intervention survey and 57 completed the post-intervention survey. Quantitative results showed the resource helped students prepare for practicals and their perception of competency and confidence when auscultating equine cardiac sounds improved ( < 0.05). Compared to fifth-year students, fourth-year students felt less competent at identifying murmurs and arrythmias prior to accessing the learning resource ( < 0.05). Fourth-year and fifth-year students' familiarity with detection of murmurs improved after completing the learning resource ( < 0.001). Qualitative analysis demonstrated a limited number of opportunities to practice equine cardiac auscultation throughout the veterinary degree, especially during the COVID-19 pandemic, and that integrated audio-visual resources are an effective means of teaching auscultation.
PubMed: 38731348
DOI: 10.3390/ani14091341 -
Identifying pediatric heart murmurs and distinguishing innocent from pathologic using deep learning.Artificial Intelligence in Medicine Jul 2024To develop a deep learning algorithm to perform multi-class classification of normal pediatric heart sounds, innocent murmurs, and pathologic murmurs.
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.
Topics: Humans; Deep Learning; Heart Murmurs; Child; Child, Preschool; Infant; Adolescent; Prospective Studies; Heart Sounds; Female; Male; Algorithms; Diagnosis, Differential; Heart Auscultation
PubMed: 38723434
DOI: 10.1016/j.artmed.2024.102867 -
Tierarztliche Praxis. Ausgabe K,... Apr 2024The objective of this study was to evaluate the signalement, clinical features, and echocardiographic findings of cats diagnosed with patent ductus arteriosus (PDA) as...
OBJECTIVE
The objective of this study was to evaluate the signalement, clinical features, and echocardiographic findings of cats diagnosed with patent ductus arteriosus (PDA) as well as short- and medium-term outcome after successful ligation of the PDA.
MATERIAL AND METHODS
Over a 10-year period 17 cats were diagnosed with PDA by transthoracic echocardiography. Thirteen cats were surgically treated by thoracotomy and ligation of the PDA.
RESULTS
In all cats, a heart murmur was detected. In 88.2% of the cases, this presented as grade 4 out of 6 murmur (15/17 cats). A continuous murmur was more common (10/17 cats; 58.9%) than a systolic murmur (7/17 cats; 41.1%). Echocardiography showed that left ventricular internal diameter end diastole (LVIDd) and left ventricular internal diameter end systole (LVIDs) were significantly above reference values in the majority of cats. Mean diameter of the PDA measured at the widest point of the vessel was 3.4 mm (± 1.08 mm) and mean maximum flow velocity amounted to 5,06 m/sec (2,6m/sec-6,4m/sec). Surgery was successfully performed in all cats treated by surgical ligation and all of these patients were discharged after postoperative inpatient therapy. One cat experienced perioperative bleeding from the PDA, which was stopped efficaciously. This cat exhibited a residual shunt directly postoperatively; this could no longer be visualized in a re-check echocardiography 3 months later. Six cats were followed over a longer period of time.
CONCLUSIONS
The surgical prognosis in this case study is very good with a postoperative survival rate of 100%.
CLINICAL RELEVANCE
Surgical treatment of PDA is curative in animals not displaying advanced cardiac lesions. The auscultation of a heart murmur can provide initial findings indicative of PDA. Therefore, cardiac auscultation is warranted at every first presentation of a kitten. It must however be taken into consideration that not every cat with PDA necessarily has a continuous murmur but may display a systolic heart murmur. Therefore, it is important give utmost attention to the patients' clinical signs.
Topics: Animals; Cats; Ductus Arteriosus, Patent; Cat Diseases; Retrospective Studies; Echocardiography; Ligation; Heart Murmurs; Female; Male
PubMed: 38701804
DOI: 10.1055/a-2290-2441 -
Tropical Medicine and Infectious Disease Apr 2024Infective endocarditis (IE) is characterised by fever, heart murmurs, and emboli. Splenic emboli are frequent in left-sided IE. A systematic review of the literature... (Review)
Review
Infective endocarditis (IE) is characterised by fever, heart murmurs, and emboli. Splenic emboli are frequent in left-sided IE. A systematic review of the literature published on splenic embolism (SE) between 2000 and 2023 was conducted. Search strategies in electronic databases identified 2751 studies published between 1 January 2000 and 4 October 2023, of which 29 were finally included. The results showed that the imaging tests predominantly used to detect embolisms were computed tomography (CT), magnetic resonance imaging, positron emission tomography (PET)/CT, single-photon emission computed tomography/CT, ultrasound, and contrast-enhanced ultrasound. More recent studies typically used F-FDG PET-CT. The proportion of SE ranged from 1.4% to 71.7%. Only seven studies performed systematic conventional CT screening for intra-abdominal emboli, and the weighted mean frequency of SE was 22% (range: 8-34.8%). F-FDG PET-CT was performed systematically in seven studies, and splenic uptake was found in a weighted mean of 4.5%. There was a lack of uniformity in the published literature regarding the frequency and management of splenic embolisation. CT scans were the most frequently used method, until recently, when F-FDG PET-CT scans began to predominate. More data are necessary regarding the frequency of SE, especially focusing on their impact on IE management and prognosis.
PubMed: 38668544
DOI: 10.3390/tropicalmed9040083