Murmurs

Question 1

What do S1 and S2 correlate to?

Answer 1

S1 - AV closing

S2 - Semilunar valves closing

Question 2

What causes the physiologic splitting of S2 and when is it heard?

Answer 2

Heard during inspiration, when the negative intrathoracic pressure results in increased venous return.

Thus it takes the right ventricle a little longer to push the deoxy blood via the pulmonary valve, therefore it shuts slightly after the aortic valve.

Question 3

What do you call the heart sounds in physiologic splitting of S2?

Answer 3

A2 P2

S1, A2, P2

Question 4

In normal people, do you always get the physiological splitting?

Answer 4

NO it alternates between normal S1 S2, then S1 A2 P2

Question 5

If you get fixed A2 P2 (continuously), what could this suggest?

Answer 5

Atrial septal defects 
Pulmonary HTN 
Right HF 
?hyperthyroidism
BBB
hypertrophic cardiomyopathy

Question 6

What could a wide split S2 suggest?

Answer 6

Pulmonary stenosis

Question 7

When is S3 heard? Explain the pathophysiology behind the sound.

Answer 7

After S2

It is due to blood bouncing back from the ventricles against the AV valves

Question 8

Differentiate between S3 and S2 splitting

What does S3 sound like?

Answer 8

S2 splitting - high pitched

S3 - lower pitched, sounds like ken-tu-cky

Question 9

Why would blood be bouncing back from the ventricles to produce the S3 sound?/Give causes of pathological S3

Answer 9

AV regurgitation
Cardiomyopathy
Heart failure

If there is volume overload, e.g. due to dilation of the ventricular walls secondary to

Question 10

Explain how AV regurgitation causes the S3 sound?

Answer 10

As the valves are ‘leaky’ i.e. they don’t close properly, the blood flows back into the ventricles, resulting in the third heart sound.

Additionally, the blood that goes back into the atrium from the ventricle ends up being put back into the ventricle during diastole, which in turn leads to volume overloading in the ventricle. This volume overloading results in ventricular hypertrophy, which actually worsens the valve defect and results in more regurgitation. Ultimately the cycle of backflow continues, resulting in the S3 sound.

Question 11

In which group of patients is the S3 sound normal?

Answer 11

Athletes
Pregnancy
Children

ABNORMAL IN ADULTS AND ELDERLY

Question 12

What is Erb’s point?

Answer 12

3/4th ICS, left sternal border, where you can here all four heart sounds