What does a diastolic murmur indicate?

From the Guidelines

A diastolic murmur is a significant clinical finding that virtually always represents a pathological condition, typically indicating valve problems such as aortic or pulmonary regurgitation, or mitral or tricuspid stenosis, and requires further cardiac evaluation with echocardiography. The presence of a diastolic murmur suggests abnormal blood flow during the heart's relaxation phase, which can be due to high blood flow rate through normal or abnormal orifices, forward flow through a narrowed or irregular orifice into a dilated vessel or chamber, or backward or regurgitant flow through an incompetent valve 1. The configuration, location, and radiation of the murmur can help determine the underlying cause, with aortic regurgitation producing a high-pitched, decrescendo murmur heard best at the left sternal border, and mitral stenosis creating a low-pitched, rumbling murmur heard at the apex. Some key points to consider when evaluating a diastolic murmur include:

• The timing of the murmur in the cardiac cycle, with diastolic murmurs occurring during the relaxation phase of the heart
• The location and radiation of the murmur, which can help determine the affected valve or chamber
• The intensity and quality of the murmur, which can provide clues to the underlying cause and severity of the condition
• The need for further evaluation with echocardiography to confirm the diagnosis and guide treatment As noted in the guidelines for the management of patients with valvular heart disease, diastolic murmurs are generally considered pathological and require further cardiac evaluation, unlike some systolic murmurs which can be benign 1. Patients with diastolic murmurs may require antibiotic prophylaxis before certain procedures if valve disease is confirmed, and some may eventually need valve repair or replacement depending on the severity and progression of their condition.

From the Research

Diastolic Murmur Indications

• A diastolic murmur can indicate important underlying valvular pathology requiring further investigation, typically with echocardiography 2
• Diastolic murmurs are often associated with valvular heart disease, such as aortic regurgitation and mitral stenosis 2
• The presence of a diastolic murmur can be a sign of pulmonary hypertension, especially in patients with severe and symptomatic valvular heart disease 3
• Diastolic dysfunction can also be a contributing factor to the development of pulmonary hypertension in patients with valvular heart disease 3

Clinical Significance

• The detection of diastolic flow disturbances in healthy individuals using pulsed Doppler echocardiography can suggest trivial pulmonary regurgitation 4
• The clinical significance of pulmonary valve regurgitation can be assessed by evaluating the distance that the flow disturbance extends from the valve and the estimated pressure difference across the valve 4
• The presence of a diastolic murmur can be an indicator of underlying cardiopulmonary disease, and further evaluation is necessary to determine the severity and significance of the condition 2, 3, 4