Heart Sounds Tutorial

Table of Contents

1. Introduction
2. The Basics
   1. Anatomy
   2. Sound
   3. Sounds II
   4. Where to listen
3. Murmurs
4. Extracardiac Sounds
5. MCQ
6. Acknowledgements and References

Sounds II

A quick recap then...

1

Tick whichever you think are true a) Opening of valves produces the normal heart sounds b) Heart sound S2 occurs with the start of systole (ventricular contraction) c) The mitral and tricuspid valves close and produce S1 d) laminar blood flow from damaged valves produces murmurs a) Correct! It's the closing of valves that produce the S1 and S2 heart soundsa) No, the closing of valves is what generates the sounds to produce the S1 and S2 heart sounds. Think of a door closing shut producing more sounds than one openingb) Correct! Heart sound S1 corresponds with the start of systoleb) No, Heart sound S1 corresponds with the start of systolec) Correct!c) Nod) Correct! Turbulent blood flow produces soundd) No, turbulent blood flow produces sounds

A little more on S3 and S4

Although it is unlikely you will hear these sounds there are a few important points to bear in mind.

S3 is a rapid filling sound from a volume overloaded system

S4 is a stretching sound of the ventricles from a pressure-overloaded system

Children and young adults (under 40) may have a normal S3 sound (physiological) but not a normal S4.

Healthy elderly adults may exhibit a normal S4 sound, especially after exercise

Physiological splitting

Physiological = Normal

Splitting = Splitting

So normal splitting of a heart sound. As you will remember from the previous page S1 and S2 are composed of two valves shutting, but at the same time and so usually you hear one sound.

However in young patients, physiological splitting of S2 can occur. S2 is made up of two components A2 and P2 (aortic and pulmonic valves respectively).

On inspiration the venous return to the heart is increased and the pulmonic valve closure is delayed enough so you can detect two sounds as shown on the diagram below. However the splitting goes away on expiration.

Note: On inspiration there can be an increase in heart rate (more accentuated in children) this is also normal and is termed sinus arrhythmia.

Splitting of the first heart sound does not normally occur.

2

Tick whichever you think are true... a) Physiological splitting can occur on inspiration and expiration b) Physiological splitting occurs with the second heart sound (S2) c) S3 can sometimes be heard in children d) With physiological splitting the aortic valve closure is the second sound a) Correct! It only occurs during inspirationa) No, it only occurs on inspirationb) Correct!b) No, scroll up and have a re-readc) Correct!c) No, scroll up and have a re-readd) Correct! It's the first sound.d) No, it's the first