Heart Sounds Flashcards
What are the normal heart sounds and what do they represent?
S1 - mitral & tricuspid valve closure, marks beginning of ventricular systole
S2 - aortic & pulmonary valve closure, marks beginning of diastole
When is S1 LOUD?
- Mitral stenosis
When is S1 SOFT?
- Mitral regurgitation
- Low cardiac output
When is the S1 intensity VARIABLE?
- AF
- Ectopic beats
- Complete heart block
What is S2 composed of?
A2 - closure of the aortic valve
P2 - closure of the pulmonary valve
What is ‘physiological splitting’?
A2 & P2 can both be heard, with P2 delayed (approx. 50ms after A2)
- Occurs on inspiration - increase in venous return to the right heart
When is physiological splitting WIDENED?
Delayed/prolonged RV emptying - RBBB - Pulmonary stenosis A2 occurs earlier (shortened LV emptying) - Ventricular septal defect - Mitral regurgitation
What is REVERSED SPLITTING and when is it heard?
A2 occurs after P2 Heard in prolonged LV emptying: - LBBB - Aortic stenosis Best heard in EXPIRATION
What is FIXED SPLITTING and when is it heard?
No variation with respiration
Characteristic of atrial septal defect
When is A2 LOUDER?
Systemic HTN
- Forceful aortic valve closure
When is A2 SOFTER?
Calcified aortic stenosis
Aortic regurgitation
When is P2 LOUDER?
Pulmonary HTN
- Forceful pulmonary valve closure
What is S3?
ABNORMAL - additional heart sound heart after S2 (‘gallop rhythm’)
- Low-pitched
- Early diastole
What does S3 represent?
Rapid ventricular filling
- Can be normal in young people, athletes, pregnancy
- Older patients = reduced LV compliance:
- Heart failure
- Aortic or mitral regurgitation
What is S4?
ABNORMAL - additional heart sound heart just prior to S1
- Low-pitched
- Late diastole
What does S4 represent?
Atrial contraction against a poorly compliant LV - ALWAYS PATHOLOGICAL
- LVH
- IHD
- HTN
- Aortic stenosis
What are 4 additional heart sounds?
Opening snap
Ejection click
Mid-systolic click
Pericardial rub
What is an ‘opening snap’ and what causes it?
High-pitched sound just after S2
- Mitral stenosis –> sudden opening of valve
- Followed by mid-diastolic murmur
Best heard at APEX or LEFT STERNAL EDGE
What is an ‘ejection click’ and what causes it?
High-pitched sound just after S1
- Aortic or pulmonary stenosis –> sudden opening of valve
- Followed by an ejection systolic murmur
Best heard at AORTIC/PULMONARY areas or LEFT STERNAL EDGE
What is a ‘mid-systolic click’ and what causes it?
High-pitched sound in mid-systole
- Mitral valve prolapse
- Usually followed by late systolic murmur
Best heard at APEX
What is a ‘pericardial rub’ and what causes it?
Scratchy sound in both systole & diastole
- Pericarditis
- Can come & go rapidly
Best heard with patient SITTING UPRIGHT at END-EXPIRATION
Name the 3 types of systolic murmur
Ejection systolic
Pansystolic
Late systolic
Describe an ejection systolic murmur and list the causes
Crescendo-decrescendo, usually preceded by Ejection Click
- Aortic stenosis (aortic area, radiates to carotids)/pulmonary stenosis (pulmonary area)
- Hypertrophic obstructive cardiomyopathy (LSE)
- Increased flow (‘flow murmurs’ - aortic area)
- Pregnancy
- Anaemia
- Fever
- L-to-R shunt (atrial septal defect)
Describe a pansystolic murmur and list the causes
Continuous throughout systole (S1-S2)
- Mitral regurgitation (apex, radiates to axilla)
- Tricuspid regurgitation (lower LSE)
- Ventricular septal defect (lower LSE)
