From the Guidelines
A heart murmur workup is essential for anyone with a newly detected heart murmur to determine its cause and significance.
Initial Evaluation
The initial evaluation should include a thorough medical history and physical examination, as well as an electrocardiogram (ECG) 1, 2.
Diagnostic Tests
The workup typically starts with a chest X-ray to assess heart size and lung fields. Echocardiography, including transthoracic echocardiogram (TTE) and possibly transesophageal echocardiogram (TEE), is then performed to visualize the heart structure and function 1, 3.
- Blood tests, such as complete blood count (CBC), blood urea nitrogen (BUN), and creatinine, may be ordered to evaluate for anemia, kidney function, and other potential causes of the murmur.
- In some cases, a cardiac MRI or CT scan may be necessary to further evaluate the heart anatomy and function.
- A stress test or exercise tolerance test may also be recommended to assess for any symptoms or changes in the murmur with exertion.
Special Considerations
- Medications such as antibiotics, like amoxicillin 2 grams orally 30-60 minutes before dental procedures, may be prescribed for patients with certain types of heart murmurs to prevent endocarditis 4.
- The frequency of follow-up appointments and further testing will depend on the underlying cause of the murmur and the patient's overall health status.
- In general, patients with innocent murmurs may require only periodic monitoring, while those with pathologic murmurs may require more frequent follow-up and potential intervention, such as surgery or catheter-based procedures 1, 2.
Key Points
- It is essential to consult a cardiologist for personalized guidance and management of a heart murmur.
- The evaluation of the patient with a heart murmur may vary greatly depending on many considerations, including the timing of the murmur in the cardiac cycle, its location and radiation, and its response to various physiological maneuvers 1, 2.
From the Research
Diagnostic Workup for Heart Murmur
The diagnostic workup for a heart murmur involves a combination of physical examination, medical history, and diagnostic tests. The following steps are typically taken:
- A thorough medical history is taken to identify any risk factors for heart disease, such as family history of heart disease, history of rheumatic fever, or exposure to certain medications during pregnancy 5, 6.
- A physical examination is performed to assess the characteristics of the murmur, including its location, intensity, and timing 5, 7.
- The physical examination also includes an assessment of vital signs, exercise capacity, and signs of congestive heart failure 5.
- Red flags that increase the likelihood of a pathologic murmur include a holosystolic or diastolic murmur, grade 3 or higher murmur, harsh quality, an abnormal S2, maximal murmur intensity at the upper left sternal border, a systolic click, or increased intensity when the patient stands 5.
Diagnostic Tests
The following diagnostic tests may be ordered as part of the workup for a heart murmur:
- Electrocardiography (ECG) and chest radiography may be ordered, but they are not always necessary and may not provide useful information in all cases 5, 6.
- Echocardiography is a key diagnostic test for evaluating heart murmurs, as it can provide detailed images of the heart and its structures 5, 7, 8.
- Referral to a pediatric cardiologist is recommended for patients with any abnormal physical examination findings, a history of conditions that increase the likelihood of structural heart disease, symptoms suggesting underlying cardiac disease, or when a specific innocent murmur cannot be identified by the family physician 5, 6.
Characteristics of Innocent and Pathologic Murmurs
Innocent murmurs are typically characterized by:
- A minor (1/6 - 2/6) intensity 7
- A crescendo-decrescendo pattern 7
- A mid-systolic timing 7
- No radiation to other areas 7 Pathologic murmurs, on the other hand, may be characterized by:
- A diastolic or continuous pattern 7, 6
- A loud or harsh quality 5, 6
- Radiation to the back or neck 6
- Signs or symptoms of cardiac disease 6