Week 4: Heart sounds and murmurs

Question 1

What is the third heart sound S3.

Answer 1

• early diastolic sound
• possibly caused by tensing of chord tendinae as raid filling of the ventricle causes expansion of the chamber
• normal finding in children and young adults
• corresponds to volume overload or CHF in adults

Question 2

What is fourth heart sound S4?

Answer 2

• late diastolic sound
• caused by atrial contraction against a noncompliant or stiffened ventricle
• usually due to ventricular hypertrophy (HTN e.g.) or MI (stiffness)

Question 3

Describe the opening snap and when it is heard?

Answer 3

• shortly after S2
• associated with mitral or tricuspid stenosis
• heard best between the apex and left sternal border

Question 4

Describe paradoxical splitting of S2 (LBBB)?

Answer 4

-P2 before A2 on inspiration and expiration because you have RV contraction before LV

Question 5

Describe wide splitting of S2.

Answer 5

• In RBBB and AD

- wide A2 and P2 on inspiration and expiration

Question 6

Describe the mechanism behind murmurs

Answer 6

• flow across partial obstruction: in aortic and mitral stenosis
• increased flow through normal structures: systolic ejection murmur
• ejection into a dilated chamber: aortic systolic murmur associated with aneurysmal dilation of the aorta
• regurgitant flow across an incompetent valve: aortic and mitral regurg
• abnormal shunting of blood from high pressure to low pressure vascular chamber: VSD

Question 7

Describe the grading of murmur intensity.

Answer 7

Systolic Murmurs
1. barely audible
2. faint
3. easily heard (1-3 are subjective)
4. heard and palpable thrill
5. very loud, scope lightly on chest
6. audible without scope on chest
Diastolic
1. barely audible
2. faint
3. easily heard
4. very loud
3+ systolic murmur should be evaluated, diastolic murmurs are never normal

Question 8

Describe murmur characteristics of aortic stenosis.

Answer 8

• systolic
• high pitched
• crescendo decrescendo
• heard best in aortic area
• radiates to carotids
• usually loud murmur

Question 9

Describe murmur characteristics of aortic regurgitation.

Answer 9

• early diastolic
• high pitched
• decrescendo
• heard best at left sternal border with patient sitting, leaning forward, and exhaling

Question 10

Describe murmur characteristics of mitral regurgitation.

Answer 10

• holosytolic
• high pitched and blowing
• uniform intensity
• heard best at apex
• radiates to left axilla

Question 11

Describe murmur characteristics of mitral stenosis.

Answer 11

• mid to late diastolic
• low pitched
• opening snap
• decrescendo with late diastolic intensification
• heard best with bell at the apex with patient in left lateral decubitus position