Structural Heart Disease Flashcards
What are some examples of congenital heart defects?
- atrial septal defect (ASD)
- ventricular septal defect (VSD)
- coarctation of aorta
- tetralogy of Fallot (TOF)
What are some examples of developed heart defects?
valvular dysfunctions
- atrial stenosis/regurgitation
muscular
- cardiomyopathies
What are structural heart diseases?
defects that affect the valves and chambers of the heart and aorta
What is diastole?
relaxation of the heart
What happens in a ventricular septal defect?
wall between the 2 ventricles fails to develop - leading to a hole
- mixing of oxygenated and deoxygenated blood
How would a baby with a ventricular septal defect present?
- poor weight gain
- palpitations
- poor eating
- cyanosis
How can you treat a ventricular septal defect?
- sometimes heals on its own
- may require open heart surgery or a catheterisation
What happens in the tetralogy of Fallot?
- ventricular septal defect
- pulmonary stenosis
- widening of the aortic valve
- right ventricular hypertrophy
- mixing of blood between ventricles and atria
What happens in pulmonary stenosis?
the pulmonary trunk is narrowed
What happens when the aortic valve widens in ToF?
the mixing of blood from both ventricles on entry to the aorta
(sits directly on ventricular septal defect)
What happens in right ventricular hypertrophy?
thickening of the right ventricle wall
What is the atrial septal defect?
hole in the wall between the 2 atria (can also be failure to develop)
What is coarctation of the aorta?
the narrowing of the descending aorta
- thickening of the left ventricle
- eventually heart failure
What is aortic/mitral stenosis?
narrowing of the aortic/mitral valve
What is aortic/mitral regurgitation?
incompetence of the aortic/mitral valve leading to back flow of blood
When is rheumatic heart disease most common?
- 25-49 (more in female)
- developing countries
When is calcific aortic valve disease most common?
> 80
When is degenerative mitral valve disease most common?
> 70 (more in female)
What are the causes of aortic stenosis?
- rheumatic heart disease
- congenital heart disease
- calcium build up
What precedes aortic stenosis?
aortic sclerosis (aortic valve thickening without flow limitation)
What is the history and presentation of aortic stenosis?
Exertional dyspnoea and fatigue
Chest pain, Angina
Syncope
Heart failure
Ejection systolic murmur
H/O Rheumatic fever, High lipoprotein, high LDL, CKD, age >65
Doppler echo is essential to the diagnosis (for the pressure gradient)
What are the risk factors of aortic stenosis?
- hypertension
- LDL levels
- smoking
- elevated CRP
- congenital bicuspid valves
- Chronic kidney disease
- Radiotherapy
- Older age
How do valves change in aortic stenosis?
- valvular endocardium is damaged due to turbulent blood flow
- age related or congenital degeneration of the valves
- Anti-strep B antibodies wrongly attack valves which initiates a inflammatory process
- leaflet fibrosis and calcium deposition limits aortic leaflet mobility and eventually leads to stenosis
What happens in rheumatic disease?
autoimmune inflammatory reaction triggered by Streptococcus infection that targets the valvular endothelium, leading to inflammation and calcification
What is the pathophysiology of aortic stenosis?
- Fibrosis and calcification of aortic valve
- Disrupted blood flow through the aortic valve
- LV contracts harder to pump blood through the stenotic valve
- continuous forceful contraction of LV causes concentric LV hypertrophy
- LV becomes stiff overtime and harder to fill leading to decreased cardiac output and diastolic dysfunction
- LV can no longer maintain normal wall stress/afterload and it increases leading to systolic heart failure
- Pressure overload in LV backs up in the left atrium causes it to dilate and ultimately leads to increase in pressure in lungs causing pulmonary congestion
How does aortic stenosis present?
- exertional dysopnea and fatigue
- chest pain
- early ejection systolic murmur (crescendo-decrescendo pattern that peaks in mid-systole, radiates to carotid)
- high lipoprotein
- rheumatic fever
- high LDL
- CKD
- age > 65
What investigations would be done for suspected aortic stenosis?
- transthoracic doppler ECG
- ECG
- Chest xray
- cardiac catheterisation
- cardiac MRI
How do you manage aortic stenosis?
primary: aortic valve replacement
- transcatheter valve replacement
- surgical valve prosthesis
- balloon aortic valvuloplasty
- antihypertensive
- ACE inhibitors
- statins
When is aortic valve replacement considered for asymptomatic aortic stenosis?
- severe AS, LV ejection fraction < 50% or undergoing another cardiac surgery
- rapidly progressing AS
- abnormal exercise test
- elevated serum B-type
- natriuretic peptide (BNP) levels
What are the congenital and acquired causes of aortic regurgitation?
- rheumatic heart disease
- infective endocarditis
- aortic valve stenosis
- congenital heart defects
- congenital bicuspid valves
What is aortic regurgitation?
diastolic leakage of blood from the aorta into the left ventricle
Why does aortic regurgitation occur?
incompetence of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root
What are the 2 different onsets of aortic regurgitation
- chronic: leading to congestive cardiac failure
- acute: medical emergency, sudden onset of pulmonary oedema (left heart failure) and hypotension/cardiogenic shock
What are the causes of aortic root dilation leading to the development of aortic regurgitation?
- Marfan’s syndrome
- connective tissue disease/collagen vascular diseases
- idiopathic
- ankylosing spondilytis
- trauma
How does acute aortic regurgitation occur?
infective endocarditis
- leads to rupture of leaflets or paravalvular leaks
- vegetations on the valvular cusps can cause inadequate closure of leaflets (blood leakage)
chest trauma - tear in the ascending aorta
How does acute aortic regurgitation present?
- cardiogenic shock
- tachycardia
- cyanosis
- pulmonary oedema
- diastolic murmur
How does chronic aortic regurgitation present?
- wide pulse pressure
- pistol shot pulse (Traube sign)
- water hammer pulse (Corrigan)
What investigations can be done for suspected aortic regurgitation
- transthoracic ECG
- chest x ray
- cardiac catheterisation
- cardiac MRI/CT scan
What is the management for acute aortic regurgitation?
- ionotropes/vasodilators
- valve replacement and repair
What is the management for chronic asymptomatic aortic regurgitation?
if LV function is normal manage by drugs or reassurance
What is the management for chronic symptomatic aortic regurgitation?
- first line: valve replacement
- adjunct vasodilator therapy
How can aortic regurgitation be prevented?
treat rheumatic fever and infective endocarditis
What is mitral stenosis?
obstruction to left ventricular inflow at the level of mitral valve due to structural abnormality of the mitral valve.
What does progression of mitral stenosis lead to?
- pulmonary hypertension
- right heart failure
What are the causes of mitral stenosis?
- rheumatic fever
- carcinoid syndrome
- SLE
- mitral annular calcification (ageing)
- use of ergot/serotonergic drugs
- amyloidosis
- rheumatoid arthritis
- whipple disease
- congenital valve deformity
When does mitral stenosis tend to occur?
decades after the episode of acute rheumatic fever.
What does the acute rheumatic fever do?
- formation of multiple foci and infiltrates in the endocardium and myocardium and along the valves
- thickens, calcified, and contracted resulting in stenosis
What is the physiology of mitral valve stenosis?
- moderate exercise or tachycardia leads to exertional dyspnoea due to increased left atrial pressure
- severe stenosis leads to an increase in LA pressure, transduction of fluid into the lung interstitium leading to dyspnoea at rest or exertion
- may lead to pulmonary hypertension
- restriction leads to limited filling of the LV, limiting cardiac output
- hemoptysis if bronchial vein rupture
How does mitral stenosis present?
- rheumatic fever
- dyspnoea
- orthopnea
- diastolic murmur
- loud S2
- neck vein distension
- hemoptysis
- 40-50 yrs old
What investigations should be done when mitral stenosis is suspected?
- ECG
- transthoracic ECG
- chest x ray
- cardiac catheterisation
- cardiac MRI/CT scan
What is the management for progressive asymptomatic mitral stenosis?
no management required
What is the management for severe asymptomatic mitral stenosis?
- no therapy generally needed
- adjuvant balloon valvotomy
What is the management for severe symptomatic mitral stenosis?
- diuretic
- balloon valvotomy
- valve replacement
- repair adjunct
- beta blockers
What is mitral regurgitation?
- abnormal reversal of blood flow from the LV to the LA
- most common valvular heart disease
What causes mitral regurgitation?
disruption in any part of the mitral valve apparatus
What factors can cause acute mitral regurgitation?
- mitral valve prolapse
- rheumatic heart disease
- infective endocarditis
- following valvular surgery
- prosthetic mitral valve dysfunction
What factors can cause chronic mitral regurgitation?
- rheumatic heart disease
- SLE
- scleroderma
- hypertrophic cardiomyopathy
- drug related
What is the pathophysiology of mitral regurgitation?
- infective endocarditis
- abscess formation
- vegetations
- rupture of chordae tendineae
- leaflet perforation
What is the physiology of chronic mitral regurgitation?
- progression leads to eccentric hypertrophy leading to elongation of myocardial fibres
- increased preload and decreased afterload
- increased LV end diastolic volume and decreased end systolic volume
- prolonged volume overload leads to LV dysfunction and increased LV end-systolic diameter
How does mitral regurgitation present?
- dyspnea
- high pitched murmur
- fatigue
- orthopnea
- chest pain
- A fib
- diminished S1
What investigations would be done in suspected mitral regurgitation?
- ECG
- transthoracic ECG
- chest xray
- cardiac catheterisation
- cardiac MRI/CT scan
How is acute mitral regurgitation managed?
- emergency surgery
- adjunct preoperative diuretics
- adjunct intra-aortic balloon counterpulsation
How is chronic asymptomatic mitral regurgitation managed?
- first line: ACE inhibitors and beta blockers
- if LV ejection fraction <60%: first line - surgery
How is chronic symptomatic mitral regurgitation managed?
- first line: surgical and medical treatment
- if LV ejection fraction if less than 30%: first line - intra-aortic balloon counterpulsation
What is a cardiomyopathy?
disease of the heart muscle that makes it harder for the heart to pump blood to the rest of your body
What are the main types of cardiomyopathies?
- dilated
- hypertrophic
- restrictive
When is dilated cardiomyopathy most common?
30-40yrs old
What is the result of dilated cardiomyopathy?
progressive, irreversible, disease causing global systolic dysfunction with heart failure
What are the primary causes of dilated cardiomyopathy?
- family history
- genetic
- idiopathic
What are the secondary causes of dilated cardiomyopathy?
- heart valve disease
- after child birth
- thyroid disease
- myocarditis
- alcoholism
- autoimmune disorders
- drugs
- mitochondrial disorders
What is the pathophysiology of dilated cardiomyopathy?
ventricular chamber enlargement and systolic dysfunction with normal left ventricular wall thickness.
What is the hallmark finding of dilated cardiomyopathy?
left ventricular dilation >4cm
Is dilated cardiomyopathy genetic?
- (rare) - autosomal dominant
- first degree relatives have a 50% chance of inheritance
What is the abnormal physiology involved in dilated cardiomyopathy and how does it cause heart failure?
- LV enlargement
- lower ejection fraction, increase in ventricular wall stress and end systolic volumes
- early compensatory mechanisms include an increase in HR and tone of the peripheral vascular system
- neurohumoral activation of the renin-angiotensin aldosterone system and an increase in circulating catecholamines
- increased natriuretic peptides
- compensatory mechanisms are overwhelmed and the heart fails.
How does dilated cardiomyopathy present?
- dyspnoea
- murmur
- fatigue
- angina
- pulmonary congestion
- low cardiac output
auscultation: - displaced apex beat
- s3 on systole
What investigations would be done if dilated cardiomyopathy is suspected?
- genetic testing
- viral serology
- ECG
- chest X ray
- cardiac catheterisation
- cardiac MRI/CT scan
- exercise stress test
- echocardiography
What is the management available for dilated cardiomyopathy?
first line: - dietary changes - fluid and sodium restrictions if heart failure: - ACEi, beta blockers - diuretics ultimately: transplantation
What is hypertrophic cardiomyopathy?
an increase in LV wall thickness that is not solely explained by abnormal loading conditions
Is hypertrophic cardiomyopathies genetic?
autosomal dominant Mendelian-inherited disease in approximately 50% of patients.
What tends to be the first clinical manifestation of hypertrophic cardiomyopathy?
- sudden death
- likely: ventricular tachycardia or fibrillation
What is the hallmark of hypertrophic cardiomyopathy?
myocardial hypertrophy that is inappropriate, often asymmetrical and occurs in the absence of an obvious stimulus.
Where does hypertrophic cardiomyopathy occur?
- in any region of the LV
- frequently involves interventricular septum - obstruction of flow from the LV outflow tract
What abnormal physiology is seen in hypertrophic cardiomyopathy?
- abnormal diastolic function
- impaired ventricular filling and increased filling pressure, despite a normal/small ventricle
- abnormal calcium kinetics and subendocardial ischemia
- profound hypertrophy and myopathic process
How does hypertrophic cardiomyopathy present?
- sudden cardiac death
- double carotid artery pulse
- syncope
- presyncope
- congestive heart failure
- dizziness
- palpitations
- angina
- ejection systolic murmur
- S3 gallop
What investigations should be done when hypertrophic cardiomyopathy is suspected?
- haemoglobin levels (check for anaemia)
- BNP
- Troponin T levels
- ECG
- Chest x ray
- cardiac MRI
Why is haemoglobin measured in suspected hypertrophic cardiomyopathy?
anaemia exacerbates chest pain and dyspnea
Why are brain natriuretic peptide (BNP) and troponin T levels measured in suspected hypertrophic cardiomyopathy?
elevated BNP, NT-proBNP, troponin T levels are associated with a increased risk of CV events, heart failure and death
How is hypertrophic cardiomyopathy treated?
- beta blockers if side effects - verapramil - add disopyramide - mechanical therapy (pace maker - short AV delay) - surgery: septal myectomy or ablation
What is restrictive cardiomyopathy?
- less well-defined
- based on estabilishing the presence of a restrictive ventricular filling pattern.
- increased stiffness of the myocardium due to familial or secondary causes
What characterises restrictive cardiomyopathy?
- diastolic dysfunction with restrictive ventricular physiology
- often normal systolic function
- atrial enlargement due to impaired ventricular filling during diastole
- volume and wall thickness of ventricles is normal
What are the causes of restrictive cardiomyopathy?
- idiopathic
- familial (troponin 1 or desmin mutations)
- haemochromatosis
- amyloidosis
- sarcoidosis
- Fabry’s disease
- carcinoid syndrome
- scleroderma
- anythracycline toxicity
- previous radiation
What are infiltrative cardiomyopathies?
deposition of abnormal substances (amyloid proteins, noncaseating granulomas, iron) in the heart tissue.
What happens during infiltrative cardiomyopathies?
- ventricular walls stiffen, leading to diastolic dysfunction
- restrictive physiology predominates in the early stages, causing conductive abnormalities and diastolic heart failure
- may lead to systolic dysfunction and ventricular arrhythmias
What abnormal physiology of restrictive cardiomyopathy that leads to heart failure?
- increased myocardium stiffness
- increase in ventricular pressures with small increases in volume
- accentuated filling occurs in early diastole and terminates at the end of the rapid filling phase
- reduced compliance/increased diastolic stiffness
- LV cannot fill enough at normal filling pressures
- reduced LV filling leads to reduced cardiac output
How do patients with restrictive cardiomyopathy present?
- comfortable in sitting position but difficulty breathing when lying dowm
- fluid in the abdomen (ascites)
- pitting edema (lower extremities)
- enlarged, sore liver
- weight loss
- cardiac cachexia
amyloidosis: - easy bruising
- periorbital purpura
- macroglossia
- carpal tunnel syndrome
- increased jugular vein present
- decreased pulse volume
What investigations should be done if restrictive cardiomyopathy is suspected?
- CBC
- serology
- amyloidosis check
- chest xray
- ECG
- catheterisation
- MRI/biopsy
How is restrictive cardiomyopathy managed?
- heart failure medication (ACEi, ARB, diuretics and aldosterone inhibitors) - antiarrhythmic therapy - immunosuppression, steroids - pacemaker - cardiac transplant
What are the clinical findings in aortic stenosis?
- Ejection Systolic murmur (Crescendo- Decrescendo)
- Syncope on exertion
- Angina on exertion
- Diffuse crackles on auscultation of lungs & Dyspnoea
What are the congenital and acquired causes of aortic regurgitation?
- Rheumatic heart disease
- Infective endocarditis
- Aortic valve stenosis
- Congenital heart defects
- Congenital bicuspid valve defects
What is systole?
Contraction of the heart
What causes chronic aortic regurgitation?
- bicuspid aortic valve
- rheumatic fever causing fibrotic changes leading to thickening and retraction of the valve leaflets
What is the pathophysiology of acute aortic regurgitation?
- increased blood volume left ventricle during systole
- Left ventricle and diastolic pressure increases
- Increase in pulmonary venous pressure
- Dyspnoa and pulmonary oedema due to back flow into lungs
- left sided heart failure
- Cardiogenic shock
What is the pathophysiology of chronic aortic regurgitation?
- Gradual increase in the left ventricle volume
- Left ventricle enlargement and eccentric hypertrophy
- ejection fraction falls and left ventricle end systolic volume rises
- left ventricle dyspnoea
- Lower coronary perfusion
- Ischaemia, necrosis and apoptosis
