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
What causes a diastolic murmur in aortic regurg
Backflow of blood through vale from aorta to LV
What causes the S3 gallop sound
Early diastole
Rapid filling and expansion of ventricles
Due to LV chronic dilation
Why can you get angina on exertion/fatigue with aortic regurg
Hypertrophy muscle -> ^ O2 demand
dec. pAorta -> compromised coronary circ
dec. SV >.: less blood flow to body
How does aortic regurg affect the lungs
Pressure build up -> pulmonary congestion
Auscultation - diffuse crackles
dyspnoea
orthopnoea - shortness of breath when lying flat
What is a bounding/Corrigan/collapsing pulse
Large SV causes bounding carotid artery during systole
drop in pressure due to leaky leaflets causes formation of vacuum during diastole, carotid “collapses”
What is the presentation of acute aortic regurgitation?
Cardiogenic shock, tachycardia, cyanosis, pulmonary oedema, diastolic murmur
What is the presentation of chronic aortic regurgitation?
Wide pulse pressure,
Corrigan sign (collapsing pulse)
What investigation is used for the diagnosis of aortic regurg
Echocardiography
Non-invasive (grade/severity)
Management of acute Aortic regurg
Medical emergency
Aortic valve replacement
Management of chronic severe Aortic regurg in asymptomatic patients
Vasodilator therapy improves haemodynamics
delays need for AVR
How can you prevent the onset of aortic regurgitation?
Treat rheumatic fever and infective endocarditis early to prevent further manifestation
What is mitral stenosis?
Obstruction to left ventricular inflow at mitral valve due to a structural abnormality
Main cause of mitral stenosis
Rheumatic fever
What can mitral stenosis progression cause
Pulmonary HTN
Right heart failure
What are the causes of mitral stenosis?
Rheumatic fever/arthritis,
Carcinoid syndrome/serotonergic drugs (5-HT causes fibrous deposits -> stiff valves),
Amyloidosis, (protein deposits)
SLE,
Describe the pathophysiology of mitral stenosis
Rheumatic fever, age related calcifications ->
Recurrent inflamm
Fibrous deposit + Calcification of mitral valve leaflet + chordae tendinae -> thick/short ChTend
Stiff leaflets
dec opening -> obstructed flow through MV
Impaired emptying of LA/filling of LV
Dec. SV/CO -> congestive heart failure
pressure back up to pulmonary arteries -> hypeertrophy and RHF
What does impaired emptying of LA in mitral stenosis lead to
^pLA -> pressure build up in lungs -> pulmonary congestion
Explain how mitral stenosis can cause right sided heart failure
Difficulty draining to LV, blood stays in pulmonary circuit (pulmonary HTN),
Right ventricle does not get pumped fully into pulmonary circuit. Eventually the increase in wall stress will lead to right sided ventricular failure
What causes the mid diastolic murmur in mitral stenosis
Turbulent blood flow across the valve
What causes A.fib in mitral stenosis
Left atrial enlargement - stretch of conduction fibres
What causes Dysphagia/Hoarseness in mitral stenosis (rare)
Left atrial enlargement - Compression of surrounding structures (oesophagus/larynx)
What can lead to cardiogenic shock/congestive heart failure
Dec. SV/CO
What can cause right sided heart failure
Right ventricular hypertrophy
Why might one get dyspnoea in mitral stenosis
^ pressure of pulmonary vasculature -> transudation of fluid in the interstitium -> Pulmonary oedema
What is cardiogenic shock
Damage to the heart resulting in its inability to efficiently pump blood around the body
What is the presentation of mitral stenosis?
history of rheumatic fever,
dyspnoea, orthopnoea
mid-diastolic murmur,
haemoptysis
A.fib
Investigations for diagnosis of mitral stenosis
ECG
CXR
Echocardiography
How can you manage severe asymptomatic mitral stenosis?
No therapy usually, but can do adjuvant balloon valvotomy
How can you manage severe symptomatic mitral stenosis?
Diuretic,
balloon valvotomy,
valve replacement,
beta blockers
What is mitral regurgitation?
Abnormal reversal of blood flow from left ventricle to left atrium, due to disruption in any part of mitral valve
What are the causes of acute mitral regurgitation?
Mitral valve prolapse,
rheumatic heart disease,
infective endocarditis,
after valvular surgery
What are the causes of chronic mitral valve regurgitation?
Rheumatic heart disease, SLE, hypertrophic cardiomyopathy
Pathophysiology of mitral regurg
Weak/Dilatation of muscle valve leaflets
Backflow of blood LV -> LA
^pLA -> ^volLV in next diastole
dilation of LV -> dec. SV/CO -> congestive heart failure
pressure build up in LA/pulmonary vasculature -> pulmonary congestion
What causes the pansystolic murmur (radiating to axilla) in mitral regurg
Blood flow consistently backwards in systole
What causes cardiogenic shock/Congestive heart failure
red. CO/SV
Why is there an increase in serum creatinine in mitral regurg
Dec. O2 to the kidneys due to red. organ perfusion - parenchymal damage
What causes the S3 heart sound in mitral regurg
^ vol pushed back to LV
What causes Peripheral oedema in mitral regurg
Congestive heart failure
What are the lung symptoms in mitral regurg and what are they caused by
red. O2 sats, tachypnoea, wheeze, crackles, frothy sputum
Fluid extravasates out of vessels and into lungs to to raised pressure.
How does mitral regurgitation present?
Dyspnoea, orthopnoea,
Pansystolic murmur
chest pain, fatigue,
S3 heart sound
What are the investigations used for the diagnosis of mitral regurg
Transthoracic echocardiography
CXR
Cardiac MRI/CT
Management of acute severe MR
Repair/replace valve structures
Management of asymptomatic chronic severe MR
watchful waiting/ surgery
Management of symptomatic chronic MR
Surgery then medical treatment
What is infective endocarditis
Infection -> inflamm of endocardium and .:valves
Can lead to aortic/mitral regurg
What is rheumatic heart disease
Heart valves permanently damaged by rheumatic fever i.e. strep infection
