Case 2

Let us ignore murmurs for this exercise. Just concentrate on heart sounds. List the sounds you hear. Describe the first heart sound. List conditions where you can hear a similar first heart sound. Explain the genesis for this finding.

Answer

Case 2 answer 

You were listening to a patient with Mitral Stenosis .

You are hearing:

• Loud first heart sound

• Crisp diastolic opening snap

• S2

The intensity of the heart sound obviously varies based on your volume setup. Compare the intensity of the first sound to second sound. Unfortunately the crisp opening snap is distracting. Let us only concentrate on the first heart sound.

List conditions where S1 is loud.

What is the mechanism to generate loud S1?

Answer

Mechanism

The intensity of S1 is determined by

• Proper closure of mitral and tricuspid valves

• LV contractility

• Distance mitral valve has to travel to shut

• Rate of heart

• High or low output

In Mitral stenosis the mitral valves are open wide at the onset of ventricular contraction and travels briskly and far to shut creating a loud sound. Whenever the valves are open wide at the onset of ventricular contraction and travel a distance to shut, result in loud sound.

Loud S1 is heard in

• Mitral stenosis

• High output states

  • Anemia

  • Thyrotoxicosis

  • Fever

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