How can you differentiate a systolic murmur from a diastolic murmur?

From the Guidelines

To determine if a heart murmur is systolic or diastolic, listen for when the murmur occurs in relation to the heart sounds, as systolic murmurs occur between S1 and S2, and diastolic murmurs occur between S2 and the next S1. Systolic murmurs are more common and typically sound like a whooshing noise after the first heart sound, while diastolic murmurs follow the second heart sound and are generally softer, higher-pitched, and more difficult to hear 1. The timing of the murmur is crucial for diagnosis because systolic murmurs often indicate conditions like aortic stenosis or mitral regurgitation, while diastolic murmurs typically suggest aortic regurgitation or mitral stenosis.

Some key points to consider when differentiating between systolic and diastolic murmurs include:

• The location and radiation of the murmur
• The presence of associated heart sounds, such as ejection clicks or opening snaps
• The response of the murmur to maneuvers, such as respiration, Valsalva, or exercise
• The presence of symptoms or signs of heart disease, such as heart failure or myocardial ischemia

According to the guidelines, echocardiography is recommended for asymptomatic patients with diastolic murmurs, continuous murmurs, holosystolic murmurs, late systolic murmurs, murmurs associated with ejection clicks or murmurs that radiate to the neck or back 1. Additionally, echocardiography is recommended for patients with heart murmurs and symptoms or signs of heart failure, myocardial ischemia/infarction, syncope, thromboembolism, infective endocarditis, or other clinical evidence of structural heart disease.

It's also important to note that the classification of murmurs can be complex, and the use of echocardiography and other diagnostic tests can help to clarify the diagnosis and guide management. For example, holosystolic murmurs are generated when there is flow between chambers that have widely different pressures throughout systole, while midsystolic murmurs occur when blood is ejected across the aortic or pulmonic outflow tracts 1.

In summary, the key to determining if a heart murmur is systolic or diastolic is to listen for when the murmur occurs in relation to the heart sounds, and to consider other factors such as the location and radiation of the murmur, associated heart sounds, and response to maneuvers. Echocardiography and other diagnostic tests can help to clarify the diagnosis and guide management.

From the Research

Determining the Type of Murmur

To determine if a murmur is systolic or diastolic, several factors must be considered:

• The timing of the murmur in relation to the cardiac cycle 2, 3, 4
• The location and radiation of the murmur on the chest wall 4
• The presence of associated clinical abnormalities, such as symptoms or other cardiac findings 2, 5, 6

Systolic Murmurs

Systolic murmurs can be further evaluated by considering the following characteristics:

• The intensity and pitch of the murmur 2, 4
• The presence of a delayed carotid upstroke or absent S2 4
• The distribution of the murmur on the chest wall, with specific patterns indicating increased aortic velocity, mitral regurgitation, or tricuspid regurgitation 4

Diastolic Murmurs

Diastolic murmurs are generally considered to indicate significant underlying valvular pathology and require further investigation, typically with echocardiography 3, 6

• The severity and characterization of diastolic murmurs by auscultation may poorly correlate with echocardiographic findings 6

Role of Echocardiography

Echocardiography is a valuable tool in evaluating systolic murmurs, particularly in patients with suspected significant heart disease 2, 5, 6, 4

• Echocardiography can provide insights into the origin of systolic murmurs and help diagnose pathologic murmurs 2, 4
• However, echocardiography should not replace cardiac physical examination, and a careful auscultation of the heart prior to the echocardiogram is mandatory 6