Valvular diseases Flashcards
What is aortic stenosis (AS)?
Refers to the narrowing and tightening of the aortic valve.
This leads to reduced blood flow from the left ventricle into the aorta and ultimately to the rest of the body.
Explain the pathophysiology of aortic stenosis?
Normal function:
- aortic valve opens to allow blood to be pumped from the left ventricle into the aorta and to the rest of the body during systole.
Aortic stenosis:
- narrowing of the aortic valve = left ventricle has to generate more pressure to enable sufficient blood to cross the aortic valve and pass into the aorta.
Leads to left ventricular hypertrophy.
Overtime, the left ventricle can no longer compensate and will start to enlarge. Therefore, ejection fraction will reduce and lead to reduced cardiac output.
Causes of aortic stenosis?
- Senile calcification: most common cause in those >65y/o.
- Congenital bicuspid valve: most common cause in those <65y/o.
- Rheumatic heart disease
- William’s syndrome: supravalvular stenosis (congenital heart defect)
Risk factors of aortic stenosis?
- over age 60
- Congenital bicuspid aortic valve
- Rheumatic heart disease
- CKD
Complications of aortic stenosis?
- Left ventricle failure
- Sudden cardiac death
Aortic stenosis symptoms?
- can be asymptomatic
- syncope
- angina
- dyspnoea on exertion
- pre-syncope
- palpitations
- left ventricular heart failure symptoms (exertional dyspnoea, orthopnoea, PND)
- can present in cardiac arrest/sudden cardiac death
Aortic stenosis signs?
Systolic murmur
- heard best on the right 2nd intercostal space
- described ‘harsh’
- radiates to the carotids
- sound is exaggerated with pt sitting forward and their breath held during expiration
Slow-rising carotid pulse
Narrow pulse pressure
Heaving, non-displaced apex beat (displaced if LVH present)
Soft S2 heart sound: absent S2 corresponds with severity.
Ejection click may be heard in some cases (early systolic)
How is aortic stenosis diagnosed?
Echocardiogram (1st line)
- Peak gradient > 40 mmHg (note, in severe left ventricular dysfunction, a low peak gradient can be falsely reassuring)
- Valve area < 1.0cm x2
- Aortic jet velocity >4 m/s
Other investigations for aortic stenosis?
ECG
- left ventricle hypertrophy (LVH) due to pressure overload.
- absent Q waves
- left axis deviation
- poor R wave progression
CXR
- cardiomegaly
- pulmonary oedema
- calcified aortic valve
Exercise testing
- assess true severity of asymptomatic pts that are physically active in addition to echocardiography
Cardiac MRI
- provide details about valve morphology, dimensions of the aortic root, and extent of valve calcification
Management of aortic stenosis?
Conservative:
- regular monitoring via echocardiogram
Medical:
Left ventricular heart failure tx
- ACEi, BB, spironolactone, hydralazine, diuretics
Surgical:
Transcatheter aortic valve implantation (TAVI)
- favoured with patients with severe comorbidities, previous heart surgery, frailty, restricted mobility, and those older than 75 years of age
Surgical aortic valve replacement (SAVR)
- favoured for patients who are low risk and less than 75 years of age.
What is aortic sclerosis?
Refers to an asymptomatic condition where parts of the tricuspid valve is calcified and thickened.
Causes of aortic sclerosis?
age-related senile degeneration of the valve
Signs of aortic sclerosis?
- ejection systolic murmur
- does not radiate to the carotids
- normal S2, pulse character, and volume
What is a heart murmur?
Refers to sound produced when blood flows abnormally through a heart valve.
Whooshing, swishing, blowing sound.
What causes a heart murmur?
Stenosis
Regurgitation
What is stenosis?
Refers to blood flowing through a valve that does not open fully as it is abnormally narrow valve.
What is regurgitation?
Refers to blood flowing backwards through a valve due to inadequate valve closure.
How do you identify heart murmurs?
- Systolic (S1) vs. diastolic (S2)
- Loudest location
- Manoeuvres that exaggerate the murmur
- Murmur radiation
Which murmurs are systolic?
Aortic stenosis
Pulmonary stenosis
Mitral regurgitation
Tricuspid regurgitation
Mitral valve prolapse
Which murmurs are diastolic?
Aortic regurgitation
Pulmonary regurgitation
Mitral stenosis
Tricuspid stenosis
What murmurs can you hear in the aortic area of the chest?
Aortic stenosis (ejection-type murmur)
What murmurs can you hear in the pulmonic area of the chest?
Pulmonary stenosis (ejection-type murmur)
What murmurs can you hear in the left sternal borders of the chest?
Aortic regurgitation
Pulmonary regurgitation
(early diastolic murmur)
What murmurs can you hear in the mitral area of the chest?
Mitral regurgitation (pansystolic murmur)
Mitral stenosis (mid-to-late diastolic murmur)
What murmurs can you hear in the tricuspid area of the chest?
Tricuspid regurgitation
Ventricular septal defect
(pansystolic murmur)
Tricuspid stenosis
Atrial septal defect
(mid-to-late diastolic murmur)
How is heart murmur graded?
Out of 6.
Grade 1/6 = very faint
Grade 2/6 = quiet
Grade 3/6 = moderately loud
Grade 4/6 = markedly loud, palpable thrill
Grade 5/6 = very loud, palpable thrill, heard with stethoscope partly off chest
Grade 6/6 = loudest, palpable thrill, heard with stethoscope entirely off chest
What is aortic regurgitation (AR)?
Refers to the aortic valve not closing properly.
This leads to backflow of blood into the left ventricle during diastole.
Pathophysiology of aortic regurgitation?
Normal:
- aortic valve closes tightly at the end of systole (S2) and prevents blood from flowing back into the left ventricle.
Aortic regurgitation:
- valve leaflets fail to close tightly due to valve disease or the aorta around the valve has dilated which allows the backflow of blood across the valve and into the left ventricle.
Aortic regurgitation symptoms?
Acute:
- sudden cardiovascular collapse
- acute pulmonary oedema
- SOB
- sweating
- pallor
- peripherally vasoconstricted
Chronic:
- can be asymptomatic
- stable angina
- dyspnoea on exertion
- orthopnoea
- PND
- palpitations
Aortic regurgitation signs?
Diastolic murmur
- Heard loudest on the left sternal border.
- Sound is exaggerated with pt sitting forward and during expiration.
- “Austin Flint” murmur (low pitched rumbling mid-diastolic murmur -best heard at apex -sign of severe aortic regurgitation.)
- Soft S1 and occasional ejection flow murmur.
- Thrill in the aortic area on palpation
- collapsing pulse -forcefully appearing and rapidly disappearing pulse, typically felt in the radial artery when holding the pt’s arm upwards.
- wide pulse pressure
What peripheral findings are seen in aortic regurgitation?
De Quincke’s sign - nail bed pulsation
Waterhammer pulse
De Musset’s sign - head hobbing/tremor
Corrigan’s sign - dancing carotids
Muller’s sign - pulsation of the uvula
Traube’s sign - pistol shot (bruit heard on auscultation of femoral pulse)
Causes of aortic regurgitation?
Acute:
- Infective endocarditis
- Aortic dissection
- Traumatic rupture of valve leaflets
- Iatrogenic causes
- Non-native aortic valve regurgitation
Chronic:
- Rheumatic heart disease
- Age-related calcification
- Congenital bicuspid aortic valve
- Connective tissue disorders: Marfan’s syndrome, Ehler’s Danlos
- Infective endocarditits
- Rheumatological conditions
How is aortic regurgitation diagnosed?
Echocardiogram (1st line)
Other IVx for aortic regurgitation (AR)?
ECG
- LVH
- p mitrale in chronic AR (p wave looks like an M)
Bloods
- inflammatory markers and blood cultures (infective endocarditis)
- auto-antibody screen (rheumatological cases)
Throat swab (group A strep)
Cardiac MRI
Management of aortic regurgitation?
Conservative:
- regular monitoring via echocardiogram
Medical:
Lower systolic BP
- BB +/- losartan (ARB)
Treat heart failure
- BASH
Surgical:
Aortic valve replacements
Complications of aortic regurgitation?
cardiovascular collapse
de novo acute heart failure
pulmonary oedema
What is mitral stenosis?
Refers to the narrowing of the mitral valve which reduces blood flow to the left ventricle.
Pathophysiology of mitral stenosis?
Normal:
- mitral valve opens during diastole to allow left ventricular filling
Mitral stenosis:
thickened and calcified mitral valve = reduces blood flow from left atrium into left ventricle during diastole = leads to reduction in end-diastolic volume in left ventricle, hence increases blood volume in left atrium = leads to atrial dilation, pulmonary congestion, right heart failure
Causes of mitral stenosis?
- Rheumatic heart disease
- Congenital mitral stenosis
- Mitral annular calcification
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis
- Carcinoid syndrome
- Infective endocarditis
Symptoms of mitral stenosis?
- dyspnoea on exertion
- orthopnoea
- PND
- palpitations -AF
- thromboembolism
- chest pain -pulmonary HTN or right ventricular hypertrophy
- hoarseness -enlarged left atrium
- haemoptysis -pink/blood stained sputum
- right side heart failure
- peripheral oedema
- hepatomegaly
Signs of mitral stenosis?
Diastolic murmur
- loudest at cardiac apex
- increases in left lateral decubitus position (left side)
- Loudest in expiration
- Heard best using stethoscope bell (low frequency)
- Loud S1 (becomes softer with increasing calcification)
- Loud P2 with pulmonary hypertension (later stages S2 splits)
- Malar flush
- Low volume pulse
- Irregularly irregular pulse -AF
- Elevated JVP
- Right ventricle heave
- Pulmonary oedema
- Tapping, non-displaced apex beat
How is mitral stenosis diagnosed?
Echocardiogram
Other iVX for mitral stenosis?
ECG
- P-mitrale (a broad notched P wave due to left atrial enlargement)
- Right ventricular hypertrophy
- Right axis deviation
- AF: caused by left atrial enlargement
CXR
- pulmonary oedema
- left atrial enlargement
Cardiac MRI
- valvular vegatations (mass)
Management of mitral stenosis?
Conservative:
- monitor regularly echocardiogram
Medical:
- AF
- rate control
- anticoagulation
- Diuretics →symptomatic relief for pulmonary congestion and peripheral oedema (right sided heart failure symptoms)
Surgical:
- Balloon valvotomy →if valve is pliable (flexible) and non-calcified.
- Percutaneous mitral valvotomy →for moderate disease
- Open valve repair/replacement
Complications of mitral stenosis?
AF
Thromboembolism
Pulmonary HTN
Dilate left atrium
