What is the grade of the heart murmur?

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Last updated: March 18, 2025View editorial policy

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From the Guidelines

The grade of the heart murmur cannot be determined solely based on the provided evidence, as it lacks specific information about the murmur's intensity, timing, and characteristics. However, according to the study 1, murmurs can be classified based on their timing and characteristics, such as holosystolic, midsystolic, early systolic, and late systolic murmurs. The study 1 also discusses the possible causes of different types of murmurs, including valvular regurgitation, stenosis, and increased flow rates. To determine the grade of a heart murmur, clinicians typically use a grading system that ranges from 1 to 6, with grade 1 being the softest and grade 6 being the loudest, as described in general medical knowledge. Key factors in assessing the grade and significance of a murmur include its intensity, timing, location, radiation, and quality, along with associated symptoms, as these can provide clues about the underlying cardiac condition 1. In clinical practice, the loudness of a murmur does not always correlate with the severity of the underlying condition, and a comprehensive assessment is necessary for accurate diagnosis and management. Some murmurs, such as those caused by valvular problems or increased flow rates, may require further evaluation with echocardiography to determine their significance and guide treatment, as noted in the study 1. Ultimately, the grade and clinical significance of a heart murmur must be evaluated in the context of the individual patient's symptoms, medical history, and physical examination findings, considering the highest quality and most recent evidence available.

From the Research

Heart Murmur Grading

  • The grade of a heart murmur is a quantitative measure of its intensity, which is strongly correlated with the patient's clinical condition 2.
  • Murmur grading schemes have been proposed to differentiate pathological and physiological murmurs or different degrees of pathology, with various clinicians contributing to these schemes over the years 3.
  • A simpler, more intuitive grading scheme might achieve the same desired outcome as more complex schemes, potentially with less confusion 3.

Murmur Grading Classification

  • Murmurs can be classified as absent, soft, or loud, with corresponding sensitivities and F1-scores for each classification 2.
  • The proposed method for automatic murmur grading from phonocardiogram achieves an unweighted average of sensitivities of 80.4% and an F1-score of 75.8% on a test set 2.
  • A system that uses the heart sounds as an internal reference for grading heart murmur intensity can quickly improve accuracy and consistency for some providers and specific murmurs 4.

Clinical Application

  • Correct diagnosis of heart conditions, such as chronic heart failure, is essential for adequate treatment, and murmur grading can be an important aspect of this diagnosis 5.
  • Treatment with angiotensin II antagonists can improve intraventricular obstruction and left ventricular hypertrophy in patients with mild hypertensive heart disease and left ventricular outflow tract obstruction 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Beyond Heart Murmur Detection: Automatic Murmur Grading From Phonocardiogram.

IEEE journal of biomedical and health informatics, 2023

Research

Murmur grading in humans and animals: past and present.

Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology, 2018

Research

Evaluation of a novel method for grading heart murmur intensity.

Archives of pediatrics & adolescent medicine, 2005

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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