Structural Heart disease - congenital/valvular Flashcards
What are 4 congenital structural heart diseases?
Atrial Septum Defect,
Ventricular Septum Defect,
Tetralogy of Fallot,
Coarctation of Aorta
What are the two groups of later onset structural heart diseases?
Valvular dysfunction and Muscular diseases (cardiomyopathies)
How does ventricular septal defect work?
Holes between two ventricles, blood moves from the left ventricle to the right ventricle due to pressure defect, causing a mix in oxygenated and deoxygenated blood
How does atrial septal defect work?
Holes between atria, blood moves from left atrium to the right atrium, causing a mix between oxygenated and deoxygenated blood
What are the abnormalities of tetralogy of fallot ?
- Pulmonary stenosis
- Right ventricular hypertrophy (caused by ^ pVentricle due to issues with perfusion to pulomary artery)
- Ventricular septal defect (RV drains to LV, ^ pressure due to hypertrophy)
- Overriding of aorta - both ventricles can drain into aorta
In tetralogy of fallot, which side does blood flow in its VSD?
Right to Left - right ventricular hypertrophy means a higher pressure on right side
How does coarctation of the aorta work?
Narrowing of any part of the aorta, limits the volume of blood that can pass through it -> red. CO/SV
What is the consequence of mixing oxygenated and deoxygenated blood?
Less oxygen delivered to the body - decreased oxygen saturation
What are 4 valvular dysfunctions?
Aortic stenosis,
Aortic regurgitation,
Mitral stenosis,
Mitral regurgitation
What is aortic stenosis?
Narrowing of aortic valve, due to leaflet fibrosis of calcium deposits on valve
Confirmed by echocardiography
What is aortic stenosis preceded by?
Aortic sclerosis (thickening of aortic valve without limiting flow)
What are the risk factors for aortic stenosis?
Hypertension, high LDL/ CRP levels, Smoking, CKD, Old Age
What are the causes of aortic stenosis?
Rheumatic heart disease, congenital heart disease, calcium buildup
Describe the pathophysiology of aortic stenosis
Valvular endocardium damaged from abnormal blood flow - injury initiates inflammatory response leading to leaflet fibrosis and calcium deposition.
This eventually leads to loss of mobility and stenosis (concentric hypertrophic LV (muscle is greater than cavity) becomes stiff ovetime and harder to fill)
How does rheumatic disease cause aortic stenosis?
Antstrep antibodies attack valves lead to valve inflammmation and calcification
Describe how aortic stenosis causes systolic heart failure
Disrupted flow through aortic valve
LV has to contract harder to pump blood due to ^afterload -> LV hypertrophy -> loss of mobility and stenosis (hypertrophic LV becomes stiff ovetime and harder to fill)
concentric hypertrophy
What is a congenital defect that can increase risk of aortic stenosis?
Bicupsid aortic valve - more prone to stenosis
What are the presentations of aortic stenosis?
Exertional dyspnoea, syncope, fatigue, chest pain-angina, ejection systolic murmur, rheumatic fever, high lipoprotein and LDL, CKD
What are the management techniques for aortic stenosis?
Transcatheter valve replacement
Surgical valve prosthesis (mechanical vs bioprosthetic)
What is aortic regurgitation?
Diastolic leakage of blood from aorta to left ventricle
Why does aortic regurgitation occur?
Incompetence of valve leaflets from intrinsic valve disease or dilation of aortic root
What are the causes of acute and chronic intrinsic valve disease for aortic regurgitation?
Acute - infective endocarditis, aortic stenosis,
Chronic - rheumatic heart disease, congenital heart & bicuspid defects
What are the causes of aortic root dilation for aortic regurgitation?
Marfan’s syndrome, idiopathic, ankylosing spondylitis, connective tissue disease
What kind of echo is essential to the diagnosis of aortic stenosis
Doppler Echo
How does acute aortic regurg present
Medical emergency
sudden onset pulmonary oedema, hypotension or cardiogenic shock
What causes inflammation of valvular endocardium leading to abnormal valve defect
Post inflammatory response
Collagen vascular disease
congenital bicuspid valve
Pathophysiology of aortic regurg
Aortic root dilatation/ Abnormal valve leaflet
Poor leaflet closure when pAorta > pLV during diastole -> backflow into LF
Volume/pressure overload in LV -> ^ preload/afterload
Causes ^ contractions/SV
What are the consequences of acute aortic regurg
Increased pressure in LV causes dilation and contractions to increase -> ^SV
Frank-Starling law
What is the frank- starling law
^ SV in response to ^ ventricular volume
As a larger volume of blood flows into the ventricle, the blood stretches cardiac muscle, leading to an increase in the force of contraction.
What are the consequences of chronic aortic regurg
LV dilates and eccentrically hypertrophies to accommodate ^ in vol
Excess stretch -> weak myocardium with contraction difficulty -> systolic heart failure