Heart Sounds

Front 1

What causes the first heart sound?

Back 1

The closing of the mitral and tricuspid valves. The mitral valve is for the LA/LV. The tricuspid valve is for the RA/RV. The mitral valve closes slightly before the tricuspid valve.

Front 2

What causes the second heart sound?

Back 2

The second heart sound is caused by the closure of the aortic and pulmonary valves. The aortic valve closes before the pulmonary valve and because the delay is longer the split can sometimes be heard. The split is widened with inspiration and narrower with expiration.

Front 3

What frequency are the third and fourth heart sounds?

Back 3

The third and fourth heart sounds are low frequency and so are heard best with the bell of the stethoscope.

Front 4

When are the third and fourth sounds heard?

Back 4

The third and fourth heart sounds are heard during diastole.

Front 5

When specifically is the third heart sound heard?

Back 5

The third heart sound is heard in early diastole at the time of maximum ventricular filling. It may be heard in fit young adults and during pregnancy.

Front 6

When specifically is the fourth heart sound heard?

Back 6

The fourth heart sound is heard at the time of atrial contraction and is therefore only present if the patient is in sinus rhythm.

Front 7

How can the third and fourth heart sounds best be heard?

Back 7

With the patient on their L side and with the bell of the stethoscope.

Front 8

What is an ejection click?

Back 8

It arises from an abnormal aortic or pulmonary valve as it opens and occur early in systole.

Hint 8

May be mistaken for splitting of the first heart sound.

Front 9

What is an opening snap?

Back 9

An opening snap arises from an abnormal mitral or tricuspid valve and is heard best in diastole. As the valve becomes more affected and the movement worsens the sound will decrease.

Front 10

What is a knock and in what pathology is it heard?

Back 10

In constrictive pericarditis there may be a loud, low frequency diastolic noise known as a knock?

Front 11

What is a pericardial rub?

Back 11

A pericardial rub is also heard in constrictive pericarditis. It is a high frequency sound, loudest in systole but sometimes extending into diastole. A rub may vary from hour to hour and will disappear if an effusion develops.

Front 12

When are murmurs from the right heart accentuated?

Back 12

During inspiration.
RILEs.

Front 13

When are murmurs from the left heart accentuated?

Back 13

During expiration.
RILEs.

Front 14

How are systolic murmurs graded?

Back 14

Out of 6.
1/6: no thrill, very quiet.
2/6: no thrill, quiet.
3/6: no thrill, easily audible.
4/6: thrill, loud.
5/6: thrill: audible with stethoscope half off chest.
6/6: thrill, audible without stethoscope.

Front 15

Where is the aortic area?

Back 15

Upper right sternal edge.

Front 16

What murmurs are best heard in the aortic area?

Back 16

Aortic stenosis, venous hum.

Front 17

How many cusps does the aortic valve usually have?

Back 17

The aortic valve usually has three equal-sized cusps.

Front 18

What happens in aortic stenosis?

Back 18

The valve may be narrowed due to fusion between the cusps, or due to a valve with only two or one cusps.
Congenital aortic stenosis - the valve annulus (ring) may be small.
The aortic valve may also be narrowed due to thickening and myxomatous (pathological weakening of connective tissue.)

Front 19

What is Shone syndrome?

Back 19

abnormal mitral valve, coarctation of aorta and small aortic valve annulus (ring).

Front 20

What is the history of aortic stenosis?

Back 20

Usually asymptomatic murmur, but patients may have angina, syncope on exercise, or even sudden death on exertion (rare).
The left ventricle will eventually fail and the patient will develop breathlessness.

Front 21

How does critical aortic stenosis present in neonates?

Back 21

In neonates, critical aortic stenosis presents as a collapsed child with absent or very feeble pulses, respiratory distress and an enlarged liver.

Front 22

What are the heart sound findings in aortic stenosis?

Back 22

Heart sounds: S1 normal, S2 normal or soft.
Added sounds: Ejection click after S1, loudest at apex.
Murmurs: Ejection systolic murmur in the aortic area radiating to the neck.

Front 23

What are the general examination findings in aortic stenosis, firstly mild, them moderate to severe?

Back 23

Mild: normal.
Mod-severe: Pulses may be of small volume, pulse pressure narrow on BP measurement, thrill in the suprasternal notch

Front 24

What does the ECG look like in aortic stenosis?

Back 24

In mild stenosis: normal.
Mod-severe: LVH and strain.

Front 25

What does the CXR look like in aortic stenosis?

Back 25

Mild: normal, posible post-stenotic dilatation of the ascending aorta.
Mod-severe: LVH, or if LVF: pulmonary oedema

Front 26

Why can a severe aortic stenosis have a silent murmur?

Back 26

If the stenosis is severe and the cardiac output is compromised, the systolic murmur is softer. If there is left ventricular failure the intensity of the murmur may be further reduced.

Front 27

Where is the murmur of aortic stenosis the loudest? Where is the click the loudest?

Back 27

The murmur is loudest in the aortic area. The click is loudest at the apex.

Front 28

What is a differential diagnosis for the murmur of aortic stenosis?

Back 28

Still's murmur is sometimes audible here but is usually louder at the lower left sternal edge.

Front 29

What makes it valvar aortic stenosis?

Back 29

The quality of the murmur, radiation into the neck, click or thrill if present.

Front 30

Where is the thrill associated with aortic stenosis?

Back 30

Mild - suprasternal notch
Mod-severe: aortic area

Front 31

What is a venous hum?

Back 31

A venous hum is a common innocent murmur of childhood and by definition the cardiac anatomy is normal. It originatse from the great veins in the neck.

Front 32

What are the great veins in the neck?

Back 32

Right internal jugular vein, right subclavian vein, innominate vein, SVC.

Front 33

When is a venous hum most commonly heard in children?

Back 33

Aged 12 months to 6 years.

Front 34

What situations of hyperdynamic circulation can cause a venous hum in adults?

Back 34

Pregnancy, thyrotoxicosis, anaemia.

Front 35

Where is a venous hum mosly heard?

Back 35

A continuous murmur, maximum above the clavicles but often audible in the aortic and pulmonary areas.

Front 36

What is the pitch of the venous hum?

Back 36

Low pitch.

Front 37

Is the venous hum more likely to be louder on the right side or the left side?

Back 37

Louder on the right side compared to left.

Front 38

How can a venous hum be accentuated?

Back 38

Look over his shoulder and upwards.
Loudest when sitting.
Disappear when lying flat.

Front 39

How can a venous hum be abolished? Which manouevres.

Back 39

Lying down.
Look in front and downwards.
Press on jugular vein (lateral to sternocleidomastoid).

Front 40

Where is the pulmonary area?

Back 40

Upper left sternal edge, second left intercostal space.

Front 41

What are the auscultatory abnormalities best heard in this region?

Back 41

ASD
Pulmonary stenosis
Innocent pulmonary flow
PDA
Loud S2

Front 42

What is an ASD?

Back 42

An ASD is a hole in the atrial septum.

Front 43

What happens to blood flow in an ASD?

Back 43

The right atrial pressure is lower than the left atrial pressure. Therefore, this allows blood to flow from the LA to the RA.

Front 44

What pathology results from blood flowing from the LA to the RA in an ASD?

Back 44

1. Increased sized of the right atrium and ventricle.
2. Increased blood flow to the lungs.

Front 45

Where is the most common place for an ASD?

Back 45

In the region of the fossa ovalis, which is normal in the foetal heart structure but not as a term baby. This is called secundum ASD.

Front 46

Where is the second most common place for an ASD?

Back 46

The hole may be at the atrioventricular valve junction and is then associated with abnormal AV valves and mitral regurgitation. This is called primum ASD.

Front 47

What is the history of an ASD?

Back 47

Often asymptomatic until complications arise in adulthood.
May be associated with chestiness and FTT in kids.

Front 48

What complications can results from the physiological changes associated with ASD?

Back 48

1. atrial or ventricular arrhythmias.
2. frequent chest infections and eventually pulmonary HTN due to increase pulmonary blood flow.
3. stroke due to paradoxical embolism.

Front 49

Which syndrome is associated with ostium primum ASDs?

Back 49

Down syndrome.

Front 50

What are the heart sounds in ASD?

Back 50

S1 normal.
S2 widely split.
No added sounds.
Systole: ejection systolic murmur, often transmitted to back.
Diastole: usually silent or soft tricuspid flow murmur. (That's because there's more blood flowing into right side of heart).

Front 51

What are the examination findings in ASD?

Back 51

Usually normal.
Right ventricular heave: pulmonary hypertension, dilated right heart.
Palpable second heart sound: pulmonary hypertension.

Front 52

What may the ECG show in an ASD?

Back 52

Usually normal.
May show a rightward axis, prolonged PR interval, RBBB.
Possible RVH if pulmonary hypertension.

Front 53

What may the CXR show in an ASD?

Back 53

A large heart, particularly the R atrium, R ventricle and central pulmonary arteries. The lung fields: plethoric.

Front 54

How does the splitting associated with the ASD change depending on the size of the ASD?

Back 54

Small: narrow splitting, may be difficult to differentiate from normal.
Large: wide fixed splitting.

Front 55

How can a pulmonary HTN hide ASD?

Back 55

The classic signs of an ASD are not found if pulmonary HTN supervenes. The pulmonary component will become accentuated and the splitting reduced.

Front 56

What is valvar pulmonary stenosis?

Back 56

Narrowing at the level of the pulmonary valve. It may be due to fusion of the commissures (joining together) of a bicuspid or tricuspid valve, or to a thickened myxomatous valve with limited movement.

Front 57

What does the narrowed valve in pulmonary stenosis cause?

Back 57

The narrow valve leads to turbulent blood flow.
The right ventricular pressure rises with increasing severity of stenosis in order to maintain blood flow to the lungs. As the stenosis becomes more severe, the right ventricle will become unable to overcome the obstruction and will fail.

Front 58

What is the history of pulmonary stenosis?

Back 58

Mild - asymptomatic.
Mod-severe: asymptomatic, may present with breathlessness and fatigue, particularly on exercise because RV can't increase its output due to obstruction.

Front 59

Why is pulmonary stenosis a problem during the neonatal period?

Back 59

The cardiac output cannot be accomodated by the right heart. This may be associated with an anatomically small right ventricle.
The baby will be well while the ductus arteriosus is patent and if the foramen ovale allows right to left shunting of blood to bypass the right ventricle, but will become severely unwell when the duct shuts.