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Updated: May 20, 2025

Ultrasonic Assessment of Myocardial Microstructure
Published on: January 14, 2014
Multiscale analysis of heart sound signals in the wavelet domain for heart murmur detection
Dixon Vimalajeewa1, Chihoon Lee2, Brani Vidakovic2
1Department of Statistics, University of Nebraska Lincoln, Hardin Hall, Lincoln, NE, 68583, USA. hvimalajeewa2@unl.edu.
Insights
This study introduces novel wavelet-based multiscale features to detect heart murmurs. These features, analyzing heart sound complexity and scaling, offer a promising, efficient method for cardiovascular disease diagnosis.
Area of Science:
- Cardiology and Biomedical Signal Processing
- Focuses on the analysis of cardiovascular sounds and the development of diagnostic tools.
Background:
- Heart murmurs, atypical heart sounds from blood flow, are critical indicators of cardiovascular disease.
- Current detection methods for heart murmurs do not fully exploit the information within heart sound signals.
- There is a need for advanced signal processing techniques to improve the accuracy and efficiency of murmur detection.
Purpose of the Study:
- To propose a new set of multiscale features for improved heart murmur detection.
- To leverage wavelet domain analysis to characterize scaling and complexity properties of heart sounds.
- To evaluate the diagnostic performance of these novel features in identifying heart murmurs.
Main Methods:
- Development of multiscale features based on fractal analysis (scaling properties) and wavelet entropy (complexity).
- Characterization of heart sound signals in the wavelet domain to extract these novel features.
- Evaluation of feature diagnostic performance using various classification algorithms, including support vector machines.
Main Results:
- The proposed wavelet-based multiscale features achieved 76.61% accuracy in detecting heart murmurs using a support vector machine classifier.
- Demonstrated competitive performance compared to existing deep learning methods.
- Required significantly fewer features than conventional approaches, indicating high efficiency.
Conclusions:
- Scaling and complexity properties of heart sounds, analyzed via wavelet domain, are potential biomarkers for cardiovascular disease.
- The proposed feature set offers a promising and efficient approach for enhancing the accuracy of heart murmur detection.
- This method provides a valuable alternative for identifying and managing cardiovascular conditions.
Abstract:
A heart murmur is an atypical sound produced by blood flow through the heart. It can indicate a serious heart condition, so detecting heart murmurs is critical for identifying and managing cardiovascular diseases. However, current methods for identifying murmurous heart sounds do not fully utilize the valuable insights that can be gained by exploring different properties of heart sound signals. To address this issue, this study proposes a new discriminatory set of multiscale features based on the scaling and complexity properties of heart sounds, as characterized in the wavelet domain. Scaling properties are characterized by examining fractal behaviors, while complexity is explored by calculating wavelet entropy. We evaluated the diagnostic performance of these proposed features for detecting murmurs using a set of classifiers. When applied to a publicly available heart sound dataset, our proposed wavelet-based multiscale features achieved 76.61% accuracy using support vector machine classifier, demonstrating competitive performance with existing deep learning methods while requiring significantly fewer features. This suggests that scaling nature and complexity properties in heart sounds could be potential biomarkers for improving the accuracy of murmur detection.
Related Concept Videos
Heart Sounds
Auscultation is the process of listening to these internal body sounds using a stethoscope. The heart produces four types of sounds, but only two—S1 and S2—can usually be heard with a stethoscope.
S1, also known as the "lub" sound, is caused by the closure of atrioventricular (A-V)...
Cardiovascular System Abnormal Findings II: Auscultation
Abnormal Heart Sounds
Gallops:
Assessment of the Cardiovascular System IV: Auscultation
Normal Heart Sounds
S1 (First Heart Sound)-
S1 is made by the closure of the mitral and tricuspid valves (atrioventricular valves), marking the beginning of systole.
S2 (Second Heart Sound)-
S2 is made by the closure of the aortic and pulmonic valves (semilunar valves), marking the end of the systole.

