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Sudden Death Related Murmurs

heart sounds auscultation


This sudden death-related murmurs module includes seven lessons. We provide a textual description, audio recording, dynamic waveform video, and a cardiac animation for each lesson. Optionally, a quiz can be taken to measure comprehension and listening skills. Users who have selected our Auscultation-Basics, Essentials or Advanced plans can print achievement certificates and view their progress and scores using our personalized dashboard.


Some murmurs are correlated with sudden death. When auscultating, take note of these murmur attributes:

  • Location
  • Timing: early, mid, late or pansystolic
  • Loudness and its pattern during systole
  • Pitch
  • Quality (harsh, blowing or musical)
  • Murmur changes during the respiratory cycle

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Sudden Death Lessons

Hypertrophic Cardiomyopathy

With hypertrophic cardiomyopathy, we can observe an early peaking, harsh, diamond-shaped systolic murmur. This murmur is present at the beginning of systole and stops well before S2. In diastole, a fourth heart sound gallop is present. The hyperdynamic left ventricle generates increased S1 sound intensity. S2 is single.

On the cardiac animation video, observe that the left ventricle contraction is strong and occurs in a reduced amount of time. The septal wall is significantly thicker than the rest of the ventricle, although this is not depicted in the animation.

The strong contraction of the left ventricle causes the anterior leaflet to be sucked into the ventricle, blocking the flow into the aorta and causing an aortic murmur. Concurrently, turbulent flow from the left ventricle to the left atrium causes a second murmur. Because these two murmurs occur simultaneously, you hear a single murmur.

Observe the difference between the two murmurs by shifting the stethoscope chestpiece from the aortic to the mitral valve area. First, you will hear the diamond-shaped aortic murmur and later the rectangular pansystolic murmur.

Hypertrophic Cardiomyopathy Lesson

Severe Aortic Stenosis

In severe aortic stenosis, a diamond-shaped systolic murmur is present throughout systole. This murmur is louder and higher-pitched than a mild aortic stenosis murmur. Calcification of the aortic valve leaflets produces this murmur.

A fourth heart sound occurs in late diastole, immediately before S1. Increased left ventricular wall thickness/stiffness produces this fourth heart sound.

S1 is normal, while S2 is louder than normal. Note that only an accentuated pulmonic component of S2 can be heard. This S2 abnormality is caused by left-side heart failure.

The aortic ejection click, heard in mild cases of valvular aortic stenosis, is not present.

Observe the significantly thickened left ventricular wall and the near-totally immobile aortic leaflets in the cardiac animation video.

Severe Aortic Stenosis Lesson

Arrhythmogenic RV Dysplasia

Arrhythmogenic RV Dysplasia is a familial abnormality associated with the replacement of the right ventricle with fibro-fatty tissue. This condition is marked by an enlarged right ventricle and decreased vigor of contraction.

The first and second heart sounds are normal. Regurgitant turbulent flow from the right ventricle into the right ventricle generates a pansystolic rectangular murmur.

Arrhythmogenic RV Dysplasia can be auscultated at the tricuspid area.

Arrhythmogenic RV Dysplasia Lesson

Mitral Valve Prolapse

This mitral valve prolapse murmur is medium pitched and diamond-shaped, beginning immediately after a mid systolic click and continuing until the end of systole.

When left ventricular volume decreases (going from supine to standing), murmur sound intensity increases, and its starting point begins earlier in systole. When left ventricular volume increases (by raising the legs while in the supine position), the murmur starts later in systole. The mid-systolic click also moves in tandem with this murmur.

On the cardiac animation video, observe that the murmur is produced by the prolapse of the posterior mitral valve leaflet. The murmur is depicted by turbulent flow from the left ventricle into the left atrium.

Mitral Valve Prolapse Lesson


This is a simulation of myocarditis taken at the apex.

  • 1. The first heart sound is softer than normal because of decreased function of the left ventricle.
  • 2. The second heart sound is normal at the mitral area.
  • 3. There is a third heart sound caused by the failure of the left ventricle.
  • 4. A rectangular, medium-pitched murmur of mild mitral regurgitation is caused by the incomplete closure of the mitral valve leaflets.

In the animated anatomy video, observe the enlarged left ventricle with decreased vigor of contraction. Also notice the regurgitant turbulent flow from the left ventricle into the left atrium which generates the murmur.

Myocarditis is often the result of a viral infection of the myocardium.

Myocarditis Lesson

Commotio Cordis

This lesson presents commotio cordis, a condition is caused by blunt force trauma to the chest, such as a baseball batter being hit in the chest by a pitch. Severe damage to the right and left ventricles and mitral and tricuspid valves may result.

In this example, the trauma is limited to the mitral valve leaflets. Rupture of a chordae tendinae has occurred, resulting in a systolic murmur. The first half of the murmur is rectangular. It is followed by a decrescendo late systolic component which is produced by rapid filling of the left atrium due to torrential mitral regurgitation.

The auscultation position is the mitral valve area.

Commotio Cordis Lesson

Ebstein's Anomaly

This is an example of Ebstein's Anomaly, a congenital abnormality. The first heart sound is increased due to thickening of the tricuspid valve leaflets. The second heart sound is normal. A rectangular murmur of tricuspid regurgitation fills all of systole. An opening snap occurs 100 milliseconds into diastole followed by a decrescendo-crescendo murmur of mitral stenosis. These findings are all a manifestation of downward displacement of the tricuspid valve into the right ventricle

In the anatomy video you can see the enlarged right atrium and the small right ventricle. The upward plume from the right ventricle to the right atrium represents the systolic murmur. The downward plume from the right atrium to the right ventricle represents the diastolic murmur.

This murmur can be auscultated at the tricuspid area.

Ebstein's Anomaly Lesson

Course Quiz

After completing all lessons in a course, a quiz becomes available. If the user successfully completes a quiz, results are saved to the user's dashboard and a certificate can be printed.

Reference Guide

For subscribers, we provide a comprehensive heart sounds and murmurs reference guide. For each abnormality, one or more sound recordings are available along with text, phonocardiogram and cardiac animation.

Authors and Sources

Authors and Reviewers


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