Structural Heart Disease Flashcards
What are some examples of congenital heart defects?
- atrial septal defect (ASD)
- ventricular septal defect (VSD)
- coarctation of aorta
- patent foramen ovale (PFO)
- patent ductus arteriosus (PDA)
- 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
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
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
What happens in pulmonary stenosis?
the pulmonary trunk is narrowed
What happens when the aortic valve widens?
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 aorta (descending)
- thickening of ventricles
- eventually heart failure
What is aortic/mitral stenosis?
narrowing of the aortic valve
What is aortic/mitral regurgitation?
incompetence of the aortic valve
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)
How would you confirm aortic stenosis?
- presence of a early-peaking, systolic ejection murmur
- confirm by ECG
What are the risk factors of aortic stenosis?
- hypertension
- LDL levels
- smoking
- elevated CRP
- congenital bicuspid valves
- Chronic kidney disease
- Radiotherapy
- Older age
What happens in aortic stenosis?
- valvular endocardium is damaged due to abnormal blood flow
- endocardial injury initiates a inflammatory process, leading to leaflet fibrosis and calcium deposition
- with limits aortic leaflet mobility and eventually stenosis
What happens in rheumatic disease?
- autoimmune inflammatory reaction triggered by Streptococcus infection that targets the valvular endothelium, leading to inflammation and calcification
What does aortic stenosis cause?
- long-standing pressure overload
- left ventricular hypertrophy
- ventricle maintains normal wall stress (afterload) despite pressure overload as the stenosis worsens, mechanism fails and ventricular wall stress increases.
- systolic function declines, with resultant systolic heart failure
How does aortic stenosis present?
- exertional dysopnea and fatigue
- chest pain
- 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 ECG
- ECG
- Chest xray
- cardiac catheterisation
- cardiac MRI
How do you manage aortic stenosis?
primary: aortic valve replacement
- balloon aortic valvuloplasty
- antihypertensive
- ACE inhibitors
- statins
When is aortic valve replacement considered for asymptomatic aortic stenosis?
- sever AS
- 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 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 chronic aortic regurgitation occur?
- bicuspid aortic valve
- rheumatic fever - fibrotic changes causing the thickening and refraction of leaflets
What is the physiology of acute aortic regurgitation?
- increased blood volume in LV during systole
- LV diastolic end pressure increases
- increased pulmonary venous pressure
- dyspnea and pulmonary oedema
- heart failure
- cardiogenic shock
What is the physiology of chronic aortic regurgitation?
- gradual increase in LV volume
- LV enlargement and eccentric hypertrophy
Early Stages - ejection fraction slightly high or normal
Then - ejection fraction falls and LV end systolic volume rises
- LV dyspnoea
- lower coronary perfusion
- ischaemia, necrosis and apoptosis
How does acute aortic regurgitation present?
- cardiogenic shock
- tachycardia
- cyanosis
- pulmonary oedema
How does chronic aortic regurgitation present?
- wide pulse pressure
- pistol shot pulse (Traube sign)