Diagnostic Approach to Heart Murmurs

Indications for Echocardiography

The American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend immediate echocardiography for patients with murmurs heard in multiple areas, particularly if they are heard in the left upper and lower sternal borders, as this may indicate structural heart disease 1, 2, 3
Echocardiography is also recommended for patients with holosystolic murmurs, diastolic murmurs, continuous murmurs, late systolic murmurs, or murmurs that radiate to the neck or back 1, 2, 3
Grade 3 or higher mid-systolic murmurs are also an indication for echocardiography 1, 2, 3

Murmurs heard in the left upper sternal border may indicate patent ductus arteriosus (PDA) or pulmonary artery stenosis, and can present as continuous or systolic murmurs 4, 5
Murmurs heard in the left lower sternal border are most likely to indicate ventricular septal defect (VSD) and typically present as holosystolic murmurs 4, 5
Murmurs heard in the right upper sternal border may indicate aortic valve disease or atrial septal defect (ASD) 5

Echocardiography is the first-line diagnostic test for evaluating heart murmurs, and should be performed immediately if possible, to assess valve morphology, atrial and ventricular septal defects, shunt lesions, ventricular function, and pulmonary artery pressure 1, 2, 3
Electrocardiography (ECG) and chest X-ray may also be performed, but should not delay echocardiography 1, 2

Low-intensity murmurs should not be ignored, as even a grade 2/6 holosystolic murmur can indicate significant chronic mitral regurgitation 4
The possibility of multiple lesions should be considered, as 35% of adults with congenital heart disease have more than one abnormal finding, with aortic and mitral valve disease being the most common combination 4, 5
Distinguishing between mid-systolic and holosystolic murmurs is important, as all holosystolic murmurs require echocardiography, while mid-systolic murmurs may not require immediate evaluation in asymptomatic patients 4, 5