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Systolic Murmurs

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This course will teach you about Systolic Murmurs. Before you take this course you should have finished our auscultation courses titled Normal, First and Second Heart Sound, and Extra Heart Sound. You should feel comfortable with the material presented.

Using this course

Each lesson in this course includes text describing the heart or lung abnormality and a simulated torso indicating the stethoscope chestpiece location. An audio recording of the sound is provided. Phonocardiograms or waveforms are included with each lesson. These waveforms can be a highly useful aid in learning to recognize heart murmurs. In addition, short videos clips illustrate the heart's motion for each abnormality. These animations indicate the origin of each murmur. Blood flow is also animated. For lung sounds, the source (location) of the sound can be revealed.

After completing a lesson, use the lesson table of contents to navigate to another lesson.

When all lessons have been completed, we recommend using the auscultation practice exercises or quiz. In order to gain a certificate of achievement, please complete the course lessons and practice drill during one session. Most users complete the course's lessons and quiz in 30-45 minutes.

Authors and Reviewers

Authors: Jonathan Keroes, MD, Cardiologist (ret.), David Lieberman, Heart Sound Simulation Consultant. Medical review by Dr. Barbara Erickson.

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Lesson #1: Innocent Murmur C26

This is an example of an innocent murmur. This type of murmur is seen with non-cardiac conditions such as pregnancy, hyperthyroidism, exercise and anemia. When these are treated appropriately the systolic murmur disappears. The murmur is heard in early systole, is of short duration and has a frequency range of 120Hz to 250Hz. It is best auscultated in the pulmonic area and increases in intensity with inspiration. It can be heard with either the bell or diaphragm. In this example S1 and S2 are normal. Diastole is silent. The short duration and mid-range frequency characterize an innocent murmur.

Lesson #2: Aortic Sclerosis (Musical Murmur)

This is a loud murmur early in systole. It has a diamond shaped appearance when viewed on the Waveform tab. The murmur is characterized by regular vibrations which give the murmur a musical quality ("cooing"). It is caused by turbulent blood flow into the aorta. S1 and S2 are normal. Diastole is silent.

Lesson #3: Aortic Stenosis -Mild

In early systole there is an aortic ejection click followed by a diamond shaped systolic murmur which ends mid-way through systole. It is a mid-frequency murmur. As the condition worsens, the murmur frequency increases. The first heart sound is normal. The second heart sound is physiologically split. The aortic component of the second heart sound is louder than normal. The anatomy video shows thickened aortic valve leaflets with decreased movement. The left ventricle wall thickness is increased.

Lesson #4: Aortic Stenosis - Severe #2

In Severe Aortic Stenosis there is a diamond shaped systolic murmur which lasts throughout systole. The murmur is loud and higher pitched than the murmur of mild aortic stenosis. It is caused by calcification of the aortic valve leaflets. There is a fourth heart sound heard in late diastole (just before the first heart sound). This is caused by the increased left ventricular wall thickness and stiffness. S1 is normal. S2 is louder than normal. In fact, you are hearing only the accentuated pulmonic component of S2 due to heart failure on the left side. The aortic ejection click heard in mild cases of valvular aortic stenosis is gone. In the anatomy video you can see the greatly thickened left ventricular wall and the almost totally immobile aortic leaflets.

Lesson #5: Mitral Regurgitation

The murmur of mitral regurgitation is a mid-frequency, rectangular murmur taking up all of systole. S1 is normal. S2 is single. There is a third heart sound gallop in diastole. Both the left ventricle and the left atrium are enlarged. The murmur is caused by turbulent flow through the incompetent mitral valve leaflets into the left atrium.

Lesson #6: Mitral Valve Prolapse (Click with Late Systolic Murmur)

There is a medium-pitched diamond shaped murmur which begins right after a mid systolic click and runs to the end of systole. The intensity of the murmur increases and its starting point begins earlier in systole as left ventricular volume decreases (going from supine to standing). The intensity of the murmur and its starting position move later in systole as the volume increases (by raising the legs while in the supine position). The mid-systolic click also moves in tandem with the murmur. On the anatomy video you can see that the murmur is caused by the prolapse of the posterior mitral valve leaflet. The murmur is represented by turbulent flow from the left ventricle into the left atrium.

Lesson #7: Hypertrophic Cardiomyopathy

An early peaking, harsh diamond-shaped systolic murmur starts at the beginning of systole and ends well before the second heart sound. A fourth heart sound gallop is also present in diastole as you can readily see on the wave form tab. S1 is increased due to a hyperdynamic left ventricle. S2 is single. On the anatomy video you can see that the contraction of the left ventricle is strong and occurs in a reduced amount of time. Anatomically, the septal wall is very much thicker than the rest of the ventricle, but this is not shown 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. At the same time turbulent flow from the left ventricle to the left atrium causes a second murmur. Since the two murmurs occur at the same time, you hear a single murmur. You can hear the difference between the two murmurs by moving the stethoscope head the aortic to the mitral valve area. First, you will hear the diamond shaped aortic murmur and later the rectangular pansystolic murmur.

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