Auscultation Flashcards
What are murmurs?
Turbulent blood flow through heart valves
What are the 3 types of murmurs?
Systolic (on contraction of the heart)
Diastolic (on relaxation)
Continuous (on contraction and relaxation)
Which heart sound occurs at the beginning of systole?
S1
Which heart sound occurs at the beginning of diastole?
S2
How can you tell if a murmur is systolic or diastolic?
Systolic murmurs coincide with the carotid pulse. Diastolic do not.
Explain physiological splitting of the second heart sound
It is normal for S2 to split on deep inspiration. Deep inspiration decreases intrathoracic pressure which increases venous return. This means the pulmonary valve shuts after the aortic valve.
With a physiologically split S2 the S2 should alternate between split and unsplit with inspiration and expiration.
Where is a split S2 best heard?
Pulmonic area. On deep inspiration.
Causes of a fixed S2?
Fixed S2:
Pulmonic stenosis
RBBB
Paradoxical S2 (P2 before A2):
Aortic stenosis
LBBB
What causes a 3rd heart sound?
The sound is related to the changes of speed of blood during passive filling of the ventricle in early diastole.
Where is a 3rd heart sound best heard?
Apex with the bell of the stethoscope.
Is a 3rd heart sound pathological or physiological?
Physiological- in young healthy patients.
Pathological- older patient with suspected or known cardiac disease- refers for echo to assess LV function
What causes a 4th heart sound?
Atrial contraction causing rapid blood flow against a stiff (less compliant) ventricle. Happens just before S1, late diastole.
Causes of a less compliant ventricle/ a 4th heart sound?
MI
Hypertension
Aortic stenosis
Where is the 4th heart sound best heard?
Apex with the bell.
Is a 4th HS pathological or physiological?
Almost always pathological. Good indicator of hypertension/aortic stenosis severity. Requires ECHO if heard to assess for LVH or Aortic stenosis.
