Cardiac Valve Defects Flashcards
What is responsible for the heart sounds heard on auscultation?
Valves snapping back shut make the heart sounds
S1 - Sound from the AV valves shutting (LUB dub)
S2 - Sound from the semi-lunar valves shutting (Lub DUB)
Additional heart sounds heard are pathological
S3 - Occurs in early diastole
- Normal in those 15-40
- Can indicate CHF in elderly
(Lub DE dub)
S4 - Due to increased stiffness of the left ventricle
- Always abnormal
(LE lub dub)
What are the 2 atrioventricular valves?
Mitral valve - Also knows an bicuspid valve, positioned between the left atrium and left ventricle
Tricuspid valve - positioned between the right atrium and right ventricle
What are murmurs?
Murmurs are a whooshing sound heard on auscultation due to turbulent blood flow
ASK MR ARMS
AS - Aortic Stenosis or Pulmonary Stenosis
MR - Mitral Regurgitation or Tricuspid Regurgitation
AR - Aortic Regurgitation or Pulmonary Regurgitation
MS - Mitral Stenosis or Tricuspid Stenosis
=> Ejection systolic murmurs:
- Aortic stenosis
- Pulmonary stenosis
- Hypertrophic obstructive cardiomyopathy
=> Pan-systolic:
- Mitral regurgitation
- Tricuspid regurgitation
- Ventricular septal defect
=> Early diastolic:
- Aortic regurgitation
- Pulmonary regurgitation
=> Mid-late diastolic:
- Mitral stenosis
What is Aortic Stenosis
- Stenosis is the failure of a valve to open completely
- Chronic process therefore its gradual development allows for compensatory changes
- Best heard on the RHS, 2nd intercostal space
S1…GAP…MURMUR
Referred to as Ejection Systolic Murmur as it is heard louder during systole
An Ejection Systolic Murmur that does not radiate to the carotid arteries is known an Aortic Sclerosis
What are the risk factors of Aortic stenosis?
- Age > 60
- Congenital Bicuspid Aortic Valve
- Rheumatic fever
- CKD
- High cholesterol levels
What are the clinical features of Aortic Stenosis?
- Chest pain
- Dyspnoea
- Syncope
What is the differential diagnosis of Aortic Stenosis?
- Aortic Sclerosis => the thickening or calcification of the aortic valve that does not cause motion restriction
- Ischaemic Heart Disease
- Hypertrophic cardiomyopathy
What are the causes of Aortic Stenosis?
- Degenerative calcification in > 65
- Bicuspid aortic valve in < 65
- Williams syndrome (supravalvular aortic stenosis)
- Post rheumatic disease
What is the pathophysiology of Aortic Stenosis?
- LV must work harder to pump blood through narrower valve, leading to compensatory LV hypertrophy
- This reduces the compliance of the LV wall, leading to LA hypertrophy and raised end diastolic pressure
- Compensatory changes allow for asymptomatic period until heart decompensates
What are the investigations one for Aortic Stenosis?
- Echo
- ECG
- Cardiac MRI
What are the routes of management of Aortic Stenosis?
- If asymptomatic then just observe
- If symptomatic than valve replacement
- If asymptomatic but valvular gradient > 40 mmHg with features such as left ventricular systolic dysfunction then consider surgery
- Aortic balloon valvuloplasty limited to those not fit for valve replacement
What is Mitral Regurgitation?
- Regurgitation if the failure of a valve to close properly
- Can be acute or chronic so clinical features depend on this
- Known as pan-systolic murmur
- Associated with collagen disorders such as Marfans Syndrome and Ehlers-Danlos Syndrome
S1…MURMUR
What are the causes of Mitral Regurgitation?
- Idiopathic weakening of valve with age
- Ischaemic heart disease
- Infective endocarditis
- Rheumatic Heart Disease
- Connective tissue disorders
What are the clinical features of Mitral Regurgitation?
- If acute then pulmonary oedema develops
If chronic then:
- Dyspnoea
- Fatigue
- Lethargy
- Displaced apex beat
- Severe MR may cause a split S2
What is the differential diagnosis of Mitral Regurgitation?
- Acute Coronary Syndrome
- Aortic Sclerosis
- Mitral Stenosis
- Infective Endocarditis
What is the pathophysiology of Mitral Regurgitation?
This depends on whether the damage to the valve is acute or chronic
IF ACUTE:
- Sudden onset of Mitral Regurgitation means there is no time for compensatory changes
- Blood backs up into LV and LA
- Eventually there is an increase in pressure in the pulmonary circulation
- Results n pulmonary oedema
IF CHRONIC:
- Gradual onset of Mitral Regurgitation allows time for compensatory LV hypertrophy and LA dilatation
- Means there is a long asymptomatic period
- Eventually heart decompensates, resulting in LV failure
What is the main investigation carried out in suspected Mitral Regurgitation?
=> ECG
- Broad P wave
=> CXR
- Cardiomegaly
=> Echo
What are the routes of management for Mitral Regurgitation?
- If mild, proceed with conservative treatment
- If more severe then repair or replace valve
Overview of Aortic Regurgitation
- Can be acute or chronic
- Known as decrescendo murmur
- Associated with Marfans Syndrome
What are the causes of Aortic Regurgitation?
=> Due to valve disease:
- Rheumatic fever
- Infective Endocarditis
- Connective tissue disorders
- Bicuspid aortic valve
=> Due to aortic root disease:
- Aortic dissection
- Ankylosing spondylitis
- Hypertension
- Syphilis
- Marfans, Ehlers-Danlos syndrome
What are the clinical features of Aortic Regurgitation?
- Collapsing pulse
- Wide pulse pressure
- Quinke’s sign (nailbed pulsation)
- De Musset’s sign (head bobbing)
What is the pathophysiology of Aortic Regurgitation?
If acute there medical emergency as blood back up into pulmonary circulation resulting in pulmonary oedema
If chronic then there is time for compensation therefore asymptomatic period
Both acute and chronic can result in cardiogenic shock
What are the investigations for Aortic Regurgitation?
CXR - shows LV hypertrophy
Echo with Doppler - assessment of severity
ECG
What are the routes of management of Aortic Regurgitation?
- Diuretics and vasodilators for mild cases
- Aortic valve replacement for severe cases
