Heart Murmur

What is a heart murmur?

A heart murmur is the sound of blood flow turbulence in the heart. Some heart murmurs are innocent while others may require referral for additional medical tests. This video provides an animated view of a heart murmur. While playing the animation, notice the heart valves and blood flow.

Heart Murmur Sounds

This section describes several important attributes of heart murmur sounds.

Timing and Cadence

Our lessons often describe heart murmur timing within a cardiac cycle. Systolic murmurs occur between the first heart sound (S1) and the second heart sound (S2). Diastolic murmurs occur between S2 and S1. In addition, timing is used to describe when murmurs occur within systole or diastole. For example, early systolic, mid-systolic or late systolic.

See our courses on systolic and diastolic murmurs for more information including audio recordings, waveforms and animations:

Auscultation Locations

Cardiac auscultation is performed systematically over five locations on the anterior chest wall. Use the stethoscope's diaphragm, switching to the bell to hear lower pitched sounds.

auscultation location areas
aortic valve auscultation location area Aortic Valve Area Second right intercostal space (ICS), right sternal border
pulmonic valve auscultation location area Pulmonic Valve Area Second left intercostal space (ICS), left sternal border
Erb's Point  auscultation location area Erb's Point Third left ICS, left sternal border
tricuspid valve auscultation location area Tricuspid Valve Area Fourth left ICS, left sternal border
mitral valve auscultation location area Mitral Valve Area Fifth ICS, left mid-clavicular line


Heart murmur duration refers to the portion of systole or diastole that the murmur occupies. Terms used include short and long. Murmurs lasting throughout systole are referred to as holosystolic or pansystolic.


Evaluation of the heart murmur's pitch should be made by classifying the pitch (frequency) as low, medium or high. The stethoscope's bell can be helpful with low pitched sounds while the diaphragm is used for medium or high pitched sounds.


A heart murmur can described by the sound's shape. Common classifications include crescendo (increasing intensity), decrescendo (decreasing intensity), crescendo-decrescendo (increasing then immediate decreasing intensity). Crescendo-decrescendo is also called diamond shaped. Rectangular, also termed plateau indicates a heart murmur of constant intensity.

Most of our lessons include a waveform with a moving cursor synchronized to the murmur audio. Many users find that the visual depiction of the murmur sounds is a useful educational tool.

heart murmur example diamond shape heart murmurs with decrescendo

Tonal Quality

Listen for additional aspects of the murmur's sounds. Heart murmurs may have qualities that can be noted as musical, harsh, blowing, booming, sharp or dull.

Respiration and Patient Position

Respiration or patient position can influence murmur intensity as well as heart sound splitting. These factors will be described within the heart sound lessons. Generally speaking, murmurs increasing with expiration originate with left side (aortic or mitral) valves, while murmurs increasing in intensity with inspiration originate with tricuspid or pulmonary valves.

Within each lesson, the author provides an sketch of the patient's position during auscultation, such as supine, left lateral decubitus, squatting or sitting.

Heart Murmur Symptoms

Patients with an abnormal heart murmur may have symptoms or signs or symptoms of the underlying cause of the murmur:

  • Chest pain
  • Fainting or dizziness
  • Bluish color on the fingertips, lips or skin
  • Chronic coughing
  • Sudden weight gain
  • Enlarged neck blood vessels
  • Shortness of breath
  • Excessive sweating even with minimal or no exertion
  • Enlarged liver
  • Infants may eat poorly or have
  • Infant failure to thrive

Heart Murmur Treatment

A heart murmur isn't a disease and does not require treatment. But some murmurs indicate an underlying condition. That condition may be treated by healthcare providers.

Heart Murmur Lessons

The following online lessons provide text, audio, dynamic waveforms and animated cardiac videos for many heart murmurs.

Systolic Murmurs
Diastolic Murmurs
Complex Conditions
Congenital Abnormalities
Cardiac Conditions Associated with Sudden Death
Auscultation in Primary Care


  • Dr. Jon Keroes
  • David Lieberman
  • Diane Wrigley, PA
  • Dr. Barbara Erikson