Structural Heart Disease Flashcards
Name congenital structural heart diseases
Atrial septal defect (ASD) Ventricular septal defect (VSD) Coarctation of aorta Patent foramen ovale (PFO) Patent ductus arteriosus (PDA) Tetralogy of Fallot (TOF)
Describe what a ventricular septal defect is
Ventricular septal defect happens when the wall between the 2 ventricles fails to develop normally in a fetus, resulting in a hole. Allows oxygenated and deoxygenated blood to mix. May present with poor weight gain, feeding, breathing difficulty. If hole small enough, closes as child grows but if large, requires open heart surgery or cardiac catheterisation to close with a badge.
Describe tetralogy of Fallot
Consists of 4 things: ventricular septal defect, pulmonary stenosis, widening of aortic valve (so widened that it sits in the ventricular wall in the septal defect) and right ventricular hypertrophy.
Describe atrial septal defect and coarctation of aorta
Atrial septal defect occurs when there is a hole in the wall between atria. Coarctation of aorta occurs when there is narrowing of the aorta. Arterial wall narrows and hence, ventricle has to push harder to eject blood. Leads to left ventricular hypertrophy and heart failure so requires urgent medical intervention.
What are common valvular defects?
Aortic stenosis - failure of aortic valve
Aortic regurgitation - incompetence of aortic valve
Mitral stenosis - narrowing of mitral valve
Mitral regurgitation - incompetence of mitral valve leading to backflow of blood
Epidemiologically what is the most common cause of valvular disease?
Rheumatic heart disease. More common in developing countries with a slightly higher prevalence in women. Mostly affects those 25-49 years of age.
Describe epidemiology of calcific aortic valve disease
Mainly affects those 70 and above. Prevalence is equal in males and females.
Who does degenerative mitral valve disease mainly affect?
Those 70 and above. More women than men.
Describe the epidemiology of aortic stenosis and what signs indicate it?
It is the second most frequent cause for cardiac surgery and largely a disease of older people (70-90).
Signs: preceded by aortic sclerosis (defined as aortic valve thickening without flow limitation) and often suspected by the presence of an early-peaking, systolic ejection murmur, and confirmed by echocardiography.
What are risk factors for aortic stenosis?
Hypertension, LDL levels, Smoking, Elevated C-reactive protein, Congenital bicuspid valve, Chronic kidney disease, Radiotherapy and old age.
CL CHORES
What are 3 causes of aortic stenosis?
- Rheumatic heart disease
- Congenital heart disease
- Calcium buildup
Describe the pathophysiology of aortic stenosis
A long standing pressure overload causes left ventricular hypertrophy. Ventricles try to maintain a normal wall stress despite the pressure overload caused by the 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 are characteristics of history and presentation of aortic stenosis?
Exertional dyspnoea and fatigue
Chest pain
Ejection systolic murmur (≥3/6 is present with a crescendo-decrescendo pattern that peaks in mid-systole and radiates to the carotid)
H/O Rheumatic fever, high lipoprotein, high LDL, CKD, age >65
What investigations are carried out for aortic stenosis?
Transthoracic echocardiography ECG Chest X ray (LVH) Cardiac catheterisation Cardiac MRI
Who is aortic valve replacement for?
Primary treatment of symptomatic AS. Also in asymptomatic patients with severe AS who have an LVEF <50% or who are undergoing other cardiac surgery. AVR may be considered in asymptomatic patients with very severe AS or severe AS with rapid progression, an abnormal exercise test, or elevated serum B-type natriuretic peptide (BNP) levels.
What other management techniques are used apart from aortic valve replacement for aortic stenosis?
Balloon aortic valvuloplasty
Antihypertensive
ACE inhibitors
Statins
What is aortic regurgitation?
Aortic regurgitation (AR) is the diastolic leakage of blood from the aorta into the left ventricle. It occurs due to incompetence of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root. AR is not as common as aortic stenosis and mitral regurgitation.
Is aortic regurgitation chronic or acute?
It can be chronic and culminate into congestive cardiac failure. Or, can be an acute medical emergency, presenting with sudden onset of pulmonary oedema and hypotension or cardiogenic shock.
What are 5 causes of aortic regurgitation?
Rheumatic heart disease, Infective endocarditis, Aortic valve stenosis, Congenital heart defects, Congenital bicuspid valves.
CARIC
What are causes of aortic root dilation?
- Marfan’s Syndrome
- Connective tissue disease/collagen vascular diseases
- Idiopathic
- Ankylosing Spondylitis
- Traumatic
MACIT
Describe the pathophysiology of acute aortic regurgitation
Increase blood volume in LV during systole causes LV end diastolic pressure to increase. Therefore, increase in pulmonary venous pressure causing dyspnea and pulmonary oedema. Leads to heart failure and cardiogenic shock.
Describe the pathophysiology of chronic aortic regurgitation
A gradual increase in left ventricular volume causes LV enlargement and eccentric hypertrophy. In the early stages, ejection fraction normal or slightly increased. Later, ejection fraction falls and LV end systolic volume rises. Eventually LV dyspnoea occurs leading to lower coronary perfusion and eventual ischemia, necrosis and apoptosis.
What are history and presentation features of acute vs chronic AR?
Acute AR - CPACT Cardiogenic shock Tachycardia Cyanosis Pulmonary edema Austin flint murmur - rumbling diastolic murmur heard best at apex of heart in 5th intercostal space at MCL.
Chronic AR
Wide pulse pressure
Corrigan’s pulse (water hammer pulse)
Pistol shot pulse (Traube sign)
What investigations are conducted for AR?
Transthoracic echocardiography
Chest X ray
Cardiac catheterisation
Cardiac MRI/CT Scan
