Cardio - Valvular Heart Diseases Flashcards
What are structural heart diseases?
defects that affect the valves + chambers of the heart + aorta
What are the 4 most common valvular heart defects?
→ aortic stenosis
→ aortic regurgitation
→ mitral stenosis
→ mitral regurgitation
What 3 heart diseases can cause valvular heart defects later on in life?
→ rheumatic heart disease
→ degenerative mitral valve disease
→ calcific aortic valve disease
What is rheumatic heart disease?
v
What is degenerative heart disease?
v
What is calcific aortic valve disease?
v
What is aortic stenosis?
→ narrowing of exit from left ventricle
→ most common valvular disease in US + Europe
→ more common in > 70 yrs
What is aortic stenosis most commonly preceded by?
aortic sclerosis = aortic valve thickening without flow limitation
How does aortic stenosis present on an ECG and on clinical examination?
→ early-peaking
→ systolic ejection murmuring
What are some risk factors that can increase the chances of getting aortic stenosis?
→ hypertension → LDL levels → smoking → elevated C-reactive protein → congenital bicuspid valves → chronic kidney disease → radiotherapy → older age
What are some causes of aortic stenosis?
→ rheumatic heart disease
→ congenital heart disease
→ calcium build-up
How can aortic stenosis result in systolic heart failure?
→ Long-standing pressure overload = left ventricular hypertrophy (LVH).
→ Ventricle to maintain a normal wall stress (afterload) despite the pressure overload produced by stenosis
→ As the stenosis worsens, the adaptive mechanism fails and left ventricular wall stress increases
→ Systolic function declines as wall stress increases, with resultant systolic heart failure
What kind of history + presentation does a patient with aortic stenosis have?
→ dyspnoea on exertion + fatigue → fatigue → ejection systolic murmur → rheumatic fever → high LDLs → CKD → age > 65
What investigation do you do if you suspect a patient has aortic stenosis?
→ transthoracic ECG
→ ECG chest X-ray
→ cardiac catheterisation
→ cardiac MRI
What is the main surgical way of treating aortic stenosis?
AVR (aortic valve replacement)
When is an aortic stenosis patient considered for AVR
→ symptomatic AS
→ Asymptomatic patients with severe AS who have an LVEF <50% or who are undergoing other cardiac surgery.
→ asymptomatic patients with very severe AS
→ asymptomatic + severe AS with rapid progression, an abnormal exercise test, or elevated serum B-type natriuretic peptide (BNP) levels
What other treatments for aortic stenosis?
→ balloon aortic valvuloplasty
→ antihypertensive
→ ACE inhibitors
→ statins
What are the 2 types of valves that can be used to replace to aortic valve?
→ mechanical
→ bioprosthetic
What are the advantages of bioprosthetic valves?
→ can do minimally invasive surgery with them
→ can insert valve without a catheter (transcatheter aortic valve implantation device)
What are some valve technologies being developed currently?
→ flexible polymeric valve
→ tissue-engineered heart valve
What is aortic regurgitation (AR)?
diastolic leakage of blood from aorta into the left ventricle
Why does aortic regurgitation occur?
incompetence of valve leaflets because of :
→ intrinsic valve disease
→ dilation of aortic root
What is chronic AR?
→ repetitive Ar
→ can culminate into congestive cardiac failure
What is acute AR?
→ medical emergency
→ presenting w sudden onset of pulmonary oedema + hypotension / cardiogenic shock
What are the congenital or acquired disease causes of AR?
→ rheumatic heart disease → infective endocarditis → aortic valve stenosis → congenital heart defects → congenital bicuspid valves
What are causes of AR related to aortic root dilation?
→ Marfan's Syndrome → connective tissue disease → collagen vascular disease → ankylosing spondylitis → trauma
How can acute AR cause cardiogenic shock?
→ Increase blood volume in LV during systole → LV end diastolic pressure increases → increase in pulmonary venous pressure → dyspnea and pulmonary oedema → heart failure = cardiogenic shock
How can chronic AR eventually lead to heart failure?
→ gradually increase in LV volume
→ LV enlargement and eccentric hypertrophy
→ at first ejection fraction is normal or slightly increased
→ after some time Ejection fraction falls and LV end systolic volume rises
→ Eventually LV dyspnoea = lower coronary perfusion
→ leads to ischaemia, necrosis and apoptosis
How does a patient present with acute AR?
→ Cardiogenic shock
→ Tachycardia
→ Cyanosis - change of body tissue colour to blue-purple due to lack of oxygen
→ Pulmonary edema
→ Austin flint murmur - low pitch rumbling heart murmur best heard in the cardiac apex
How does a patient present with chronic AR?
→ wide pulse pressure
→ corrigan (wate hammer pulse)
→ pistol shot pulse (Traube sign)
What investigations do you carry out if you suspect a patient has AR?
→ transthoracic ECG
→ chest x-ray
→ cardiac catheterisation
→ cardiac MRI / CT scan
How is acute AR managed / treated?
→ lonotropes / vasodilators
→ valve replacement / repair
How is chronic asymptomatic AR managed / treated?
if LV function is normal, can be managed with drugs or reassurance
How is chronic symptomatic AR managed / treated?
first line = valve replacement + adjunct vasodilator therapy
How can AR be prevented?
treat any disease causes (e.g. rheumatic fever or infective endocarditis) before it can progress to AR
What is mitral stenosis?
obstruction to left ventricular inflow at level of mitral valve due to structural abnormality of mitral valve
What is the main cause of mitral valve stenosis?
rheumatic fever in developing countries
What are some other causes of mitral stenosis?
→ Carcinoid syndrome → Use of ergot/serotonergic drugs → SLE → Mitral annular calcification due to aging → Amyloidosis → Rheumatoid arthritis → Whipple disease → Congenital deformity of the valve
What can progression of mitral stenosis lead to?
→ pulmonary hypertension
→ right heart failure
What is the pathophysiology of mitral stenosis?
→ severe mitral stenosis
causes increase in left atrial pressure
→ transduction of fluid into lung interstitium
→ causes dyspnoea at rest + exertion
→ pulmonary hypertension may also develop
→ restricted filling of left ventricle limits cardiac output
→ can cause hemoptysis is bronchial vein ruptures
How does a patient with mitral stenosis present?
→ history of rheumatic fever → dyspnoea → orthopnoea → diastolic murmur → loud P2 → neck vein distention → hemoptysis
What investigations do you perform on a patient you suspect has mitral stenosis?
→ ECG → transthoracic ECG → chest x-ray → cardiac catheterisation → cardiac MRI / CT scan
How do you manage progressive but asymptomatic mitral stenosis?
no therapy required
How do you manage severe asymptomatic mitral stenosis?
no therapy generally required adjuvant balloon valvotomy
How do you manage severe symptomatic mitral stenosis?
→ diuretic
→ balloon valvotomy
→ valve replacement + repair
→ adjunct beta-blockers
What is mitral regurgitation?
leakage of blood from left ventricle into the left atrium
What are the causes of acute mitral regurgitation?
→ Mitral valve prolapse → Rheumatic heart disease → Infective endocarditis → Following valvular surgery → Prosthetic mitral valve dysfunction
What are the causes of chronic mitral regurgitation?
→ Rheumatic heart disease → SLE → Scleroderma → Hypertrophic cardiomyopathy → Drug related
How does chronic MR progress?
→ progression leads to eccentric hypertrophy
→ leading to elongation of myocardial fibres and increased left end diastolic volume
→ Increase in preload & a decrease in afterload
→ increase in end- diastolic volume + decrease in end-systolic volume
What is the history + presentation of chronic MR?
→ dyspnoea → fatigue → diminished S1 → orthopnoea → atrial fibrillation → high-pitched murmur → chest pain
What are some investigations for MR?
→ ECG → transthoracic ECG → chest x-ray → cardiac catheterisation → cardiac MRI / CT scan
How is acute MR managed?
→ emergency surgery
→ adjunct preoperative diuretics
→ adjunct intra-aortic balloon counter-pulsation
How is chronic asymptomatic MR managed?
→ ACE inhibitors
→ beta blockers
→ surgery later if necessary
When is chronic asymptomatic MR treated with surgery?
left ventricular ejection fraction less than 60%
How is chronic symptomatic MR managed?
→ first-line = surgery + medical treatment
→ intra-aorthic balloon counter-pulsation
When is chronic asymptomatic MR treated with intra-aorthic balloon counter-pulsation?
left ventricular ejection fraction is less than 30%
