From the Guidelines
A grade 1 heart murmur is typically considered benign and does not require further evaluation or treatment unless associated with symptoms or other cardiac abnormalities. This is based on the fact that echocardiography is not recommended for patients with grade 2 or softer midsystolic murmurs identified as innocent or functional by an experienced observer, as stated in the 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease 1.
Clinical Significance
The clinical significance of a grade 1 heart murmur is generally minimal, as it is often innocent or physiologic, especially in certain populations such as children, pregnant women, and athletes. These murmurs are very soft and barely audible, even with a stethoscope, and require optimal listening conditions to detect.
Evaluation and Management
According to the guidelines, echocardiography with color flow and spectral Doppler evaluation can provide important information regarding valve morphology and function, but it is not necessary for all patients with cardiac murmurs, particularly those with short grade 1 to 2 midsystolic murmurs and otherwise normal physical findings 1. However, if a grade 1 murmur is detected, healthcare providers may recommend routine follow-up, and in some cases, an echocardiogram may be ordered if there are other concerning features such as symptoms of heart disease, abnormal heart sounds, or relevant family history to rule out structural heart problems.
Key Points
- Grade 1 murmurs are often innocent or physiologic
- Echocardiography is not typically recommended for grade 1 murmurs unless associated with symptoms or other cardiac abnormalities
- Routine follow-up may be recommended, but specific intervention is usually not needed
- Further evaluation with echocardiogram may be considered if other concerning features are present 1
From the Research
Clinical Significance of Grade 1 Heart Murmur
- A grade 1 heart murmur is generally considered to be a low-risk finding, but it can still be a sign of underlying heart disease 2, 3.
- The clinical significance of a grade 1 heart murmur depends on various factors, including the patient's age, medical history, and physical examination findings 2, 3.
- In children, a grade 1 heart murmur is often considered innocent, but it can still be a sign of underlying heart disease, such as a septal defect or pulmonary outflow tract abnormality 2, 3.
- In adults, a grade 1 heart murmur can be a sign of mitral valve prolapse, aortic stenosis, or other valvular abnormalities 4, 5, 6.
- Echocardiography is often recommended to evaluate the cause of a heart murmur, especially if it is grade 3 or higher, or if there are other signs of heart disease 2, 5, 3.
Diagnostic Evaluation
- Physical examination is an important part of the diagnostic evaluation of a heart murmur, and can help identify signs of underlying heart disease, such as a harsh quality murmur, an abnormal S2, or increased intensity when standing 2, 3.
- Electrocardiography and chest radiography are not always helpful in diagnosing the cause of a heart murmur, but can be useful in evaluating for signs of heart disease 2.
- Echocardiography is the diagnostic tool of choice for evaluating the cause of a heart murmur, and can help identify valvular abnormalities, septal defects, and other heart diseases 4, 5, 6.
Management
- The management of a grade 1 heart murmur depends on the underlying cause, and can range from reassurance and monitoring to surgical intervention 2, 4, 6, 3.
- Patients with a grade 1 heart murmur should be referred to a cardiologist if there are signs of underlying heart disease, or if the murmur is associated with symptoms such as chest pain or shortness of breath 2, 3.