Heart sounds

Question 1

What is S1, the first heart sound?

Answer 1

Caused by closure of the mitral and tricuspid valves

Question 2

What is S2, the second heart sound?

Answer 2

Caused by the closure of the aortic and pulmonary valves

Question 3

What is S3?

Answer 3

Caused by diastolic filling of the ventricle

Question 4

When is hearing an S3 considered normal?

Answer 4

Normal if < 30 years old (may persist in women up to 50 years old)

Question 5

What conditions may cause an S3?

Answer 5

Heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock) and mitral regurgitation

Question 6

What is S4?

Answer 6

Caused by atrial contraction against a stiff ventricle

- therefore coincides with the P wave on ECG

Question 7

What conditions can cause an S4?

Answer 7

• Aortic stenosis
• HOCM (a double apical impulse may be felt as a result of a palpable S4)
• Hypertension

Question 8

Where do you ausculate the pulmonary valve on the chest?

Answer 8

Left second intercostal space, at the upper sternal border

Question 9

Where do you ausculate the aortic valve on the chest?

Answer 9

Right second intercostal space, at the upper sternal border

Question 10

Where do you ausculate the mitral valve on the chest?

Answer 10

Left fifth intercostal space, just medial to mid clavicular line

Question 11

Where do you ausculate the tricuspid valve on the chest?

Answer 11

Left fourth intercostal space, at the lower left sternal border