CLIN SKILLS: Auscultation

Question 1

what produces heart sounds?

Answer 1

• CLOSURE of valves

Question 2

what are the 2 main heart sounds

Answer 2

• S1 “lub” = closure of AV valves (low pitch, longer duration)
• S2: “dup” = closure of SL valves (higher pitch, shorter duration)

Question 3

heart sound S3

Answer 3

• low-pitched, early diastolic
• best heard at apex
• can be normal in small children or vigorous exercise
• can be pathological if reduced ventricular compliance
• associated with rapid passive filling of LV

Question 4

heart sound S4

Answer 4

• late diastole
• caused by atrial systole
• can be normal in children but usually abnormal in adult

Question 5

splitting of S2

Answer 5

• normal split on inspiration
• aortic valve component and pulmonary valve component
• due to early closure of aortic valve or late closure of pulmonary valve

Question 6

paradoxical S2 split

Answer 6

• not the same as pulsus paradoxus
• closure of aortic valve occurs AFTER pulmonary valve
• caused by aortic stenosis or LBBB

Question 7

systolic vs diastolic murmurs

Answer 7

• systolic: between S1 and S2
  (aortic stenosis and mitral regurgitation)
• diastolic: between S2 and S1 (mitral stenosis and aortic regurgitation)

Question 8

opening snap of mitral stenosis

Answer 8

• early diastolic sound

Question 9

systolic clicks

Answer 9

• high pitched sounds
• ejection clicks: abrupt opening of semilunar valves and heard just after S1 - usually due to bicuspid aortic valve
• non-ejection clicks: mid-late systole = tensing of the chordae tendineae in mitral or tricuspid prolapse

Question 10

pericardial friction rub

Answer 10

• high-pitched sound caused by friction of inflamed pericardium
• best heard leaning forward on inspiration, at apex of heart
• nearly 100% specific for pericarditis