1b Structural Heart Disease Flashcards
Which side of the heart is the bicuspid (mitral) valve on?
Left side
Which side of the heart is the tricuspid valve on?
The right side
What do structural heart diseases cover?
Number of defects which affect the valves and chambers of the heart
What are some examples of congenital heart diseases?
Atrial Septum defects
Ventricular septem defects
Coarctation of Aorta
Tetralogy of Fallot
Which are the examples of Structural Heart Disease which develops later in life?
Due to valvular dysfunction - Atrial Stenosis / regurgitation or muscular (cardiomyopathies)
Describe the pathology which occurs in Atrial and Ventricular Septum Defects?
Holes between either ventricles or atria - separates left and right
therefore, there is mixing of the blood which is oxygenated and deoxygenated
Left = under higher pressure so when right blood enters into left = results in overload and hypertension leading to right sided heart failure
What are the four problems in Tetralogy of Fallot?
- Over riding aorta
- Right ventricular hypertrophy
- Ventricular septum defects
- Pulmonary Valve Stenosis
What is coarctation of the aorta?
When the wall of the aorta bends in on itself and becomes constricted, reducing stroke volume and cardiac output resulting in breathlessness
What are the four types of valvular defects?
Aortic Stenosis / Regurgitation
Mitral Stenosis / Regurgitation
Can you get pulmonary / tricuspid defects?
Yes but they are significantly more uncommon
What two things indicate aortic stenosis?
Early peaking, systolic ejection murmur - confirmed through echo
What preceeds aortic stenosis?
aortic sclerosis
What is aortic sclerosis?
Aortic valve thickening without flow limitation
What are the risk factors associated with Aortic Stenosis?
Hypertension
High LDL
Smoking
CRP
CKD
Radtiotherapy
What are the causes of Aortic Stenosis?
Rheumatic Heart Disease
Congenital Heart Disease
Calcium Build Up
Why is a murmur present in aortic stenosis?
When there is blood which is force flowing against calcified wall results in a murmur
What happens to the valvular endocardium in aortic stenosis?
The valvular endocardium is damaged as the result of abnormal blood flow across the valve (in the case of a bicuspid valve) or by an unknown trigger.
Why is calcium deposited on the valve?
Endocardial injury initiates an inflammatory process similar to atherosclerosis and ultimately leads to leaflet fibrosis and deposition of calcium on the valve.
What leads to stenosis?
Progressive fibrosis and calcium deposition limit the leaflet mobility and eventually produce stenosis
Why does rheumatic disease lead to AS?
Autoimmune inflammatory reaction = triggered prior to streptococus infection which targets the valvular endothelium, leads to inflammation and eventually calcification
How can AS lead to heart failure?
Long standing pressure overload -> left ventricular hypertrophy as more blood in the left ventricle
Ventricle does try to maintain normal wall stress (afterload) despite the increased pressure caused by the stenosis
Eventually this becomes too much, so systolic function declines as wall stress increases resulting in systolic heart failure
What type of murmur will be present in patient with Aortic Stenosis?
Ejection systolic murmur (≥3/6 is present with a crescendo-decrescendo pattern that peaks in mid-systole and radiates to the carotid)
What symptoms might someone with Aortic Stenosis have?
Exertional dyspnoea
fatigue
Chest Pain
What four investigations should be done for a patient with suspected Aortic Stenosis?
Transthoracic echocardiography
ECG Chest X ray (LVH)
Cardiac catheterisation
Cardiac MRI
What is the primary treatment of symptomatic AS?
Aortic Valve Replacement
What conditions might AVR be considered for asymptomatic patients?
Severe AS, abnormal exercise test, elevated serum B-type natriuretic peptide levels
What other medications might someone with AS be placed on?
Anti-hypertensives
ACE Inhibitors
Statins
What is Aortic regurgitation?
The diastolic leakage of blood from the aorta into the left ventricle
What does acute aortic regurgitation present as?
medical emergency - sudden onset pulmonary oedema and hypotension or cardiogenic shock
What are the congenital causes of Aortic Regurgitation?
RDH
Infective endocarditis
Aortic valve stenosis
Congenital Heart defects
Congenital Bicuspid valves
Why does Aortic regurgitation occur?
due to incompetence of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root
What are the causes of Aortic regurgitation?
Marfans Syndrome
Connective Tissue Disease
Trauma
Collagen Vascular Diseases
How does acute AR happen?
Infective Endocardtis -> rupture of leaflets
Vegetations on the valvular cusps -> cause inadequate closure of leaflets
Chest trauma -> tear in ascending aorta
How does rheumatic fever cause AR?
Fibrotic changes cause thickening and retraction of leaflets
Describe how Acute Aortic Regurgitation leads to a cardiogenic shock?
Increase blood volume in LV during systole -> LV end diastolic pressure increases- > increase in pulmonary venous pressure -> dyspnea and pulmonary oedema -> heart failure -> cardiogenic shock
How does chronic AR differ from acute AR?
Chronic - the increase in LV volume is gradual = so leads to LV enlargement and eccentric hypertrophty
Eventually, the ejection fraction falls and systolic volume rises, leading to eventual dyspnoea -> lower coronary perfusion -> ischemia, necrosis and apoptosis
Which three signs are distinctive of Chronic Aortic regurgitation?
Wide pulse pressure
Corrigan (wate hammer pulse)
Pistol shot pulse (Traube sign)
What are the presentations of Acute Aortic Regurgitation?
Cardiogenic shock
Tachycardia
Cyanosis
Pulmonary edema
Austin flint murmur
What is the management plan for Acute AR?
Valve replacement, repair, with vasodilators
What is the management plan for chronic asymptomatic AR?
If LV function is normal can be managed by drugs or reassurance
What is the management plan for chronic symptomatic AR?
First line = valve replacement with adjunct vasodilator therapy
How can AR 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 is the main cause of Mitral Stenosis?
Rheumatic Fever
what is the prognosis of Mitral Stenosis?
Pulmonary hypertension and right heart failure
What does an acute insult to the mitral valve result in?
Acute insult leads to formation of multiple foci and infiltrates in the endo and myocardium and along the walls of the vales
What happens to the left atrial pressure in Mitral Stenosis?
Increased
Why does Mitral Stenosis lead to exertional dyspnoea?
Severe mitral stenosis leads to increase in left atrial pressure , transudation of fluid into the lung interstitium leading to dyspnoea at rest or exertion
Why does cardiac output decrease in Mitral Stenosis?
Restricted orifice limits the filling of the left ventricle limiting cardiac output
What might a patient with Mitral Stenosis present with?
H/0 of Rheumatic fever
Dyspnoea
orthopnoea
Diastolic murmur
Loud P2
Neck vein distention
Hemoptysis
What extra investigation might you conduct on a patient with suspected Mitral Stenosis?
ECG
What is the treatment plan for severe asymptomatic Mitral Stenosis?
No therapy required, sometimes might do adjuvant balloon valvotomy
What is the treatment plan for severe symptomatic Mitral Stenosis?
Diuretic, balloon valvotomy, valve replacement, repair adjunct, B Blockers
What is mitral regurgitation?
Abnormal reversal of blood flow from the left ventricle to the left atrium.
What are the causes of acute mitral regurgitation?
RDH
Infective endocarditis
Mitrl Valve Prolapse
Valvular surgery
Prosthetic mitral valve dysfunction
What are the causes of chronic Mitral Regurgitation?
RDH
DLE
Scleroderma
Hypertrophic cardiomyopathy
How does infective endocarditis lead to Mitral Regurgitation?
Infectious endocarditis: Abscess formation, vegetations, rupture of chordae tendineae and leaflet perforation
Describe the abnormal physiology associated with Mitral Regurgitation?
progression leads to eccentric hypertrophy leading to elongation of myocardial fibres and increased left end diastolic volume Increase in preload & a decrease in afterload increase in end- diastolic volume and a decrease in end-systolic volume
Which heart condition might you have atrial fibrillation?
Mitral Regurgitation
What might someone with Mitral Regurgitation present with?
Dyspnea diminished S1, murmur high
Fatigue pitched, blowing xx
Orthopnea
Chest pain
Atrial fibrillation
What is the treatment plan for acute MR?
Emergency Surgery adjunct preoperative diuretics adjunct intra-aortic balloon counterpulsation
What is the treatment plan for Chronic Asymptomatic MR?
1st ACE inhibitors
Beta blockers if left ventricular ejection fraction is less than 60%
1st line is surgery
What is the treatment plan for Chronic Symptomatic MR?
Surgery + medical treatment is first line
if left ventricular ejection fraction is less than 30% 1st line is Intra-aortic balloon counterpulsation
What is a cardiomyopathy?
Cardiomyopathy is a disease of the heart muscle that makes it harder for heart to pump blood to rest of your body
What are the three types of cardiomyopathies?
Dilated
Hypertrophic
Restrictive
What are the causes of secondary cardiomyopathies?
Alcoholism
Auto-immune
Ingestion of drugs
Thyroid Disorders
Mitochondrial Disorders
Heart Valve Disease
What is Dilated cardiomyopathy characterised by?
Dilated cardiomyopathy is characterized by ventricular chamber enlargement and systolic dysfunction with normal left ventricular wall thickness.
What are the early compensatory mechanisms for Dilated CM?
Increase in heart rate and tone of the peripheral vascular system
What happens to the ventricle and hence ejection raction in Dilated CM?
Ventricle enlarges
Lower ejection fraction and increase in the ventricular wall stress and end systolic volumes
What changes occur to the renin and angiotensin system?
neurohumoral activation, and increase in circulating levels of catecholaminew
What happens to natureitic peptide levels in Dilated Cardiomyopathy?
levels of natriuretic peptides are also increased.
What would a patient with dilated cardiomyopathy present with?
Dyspnoea, displaced apex beat, S3 or systolic murmur
fatigue,
angina,
pulmonary congestion
low cardiac output
What investigations should you do for someone with dilated CM?
Genetic Testing
Viral serology
ECG
Chest X ray
Cardiac catheterisation
Cardiac MRI/CT Scan
Exercise stress test
Echocardiography
What is the management of Dilated CM?
Ace Inhibitors
Beta Blockers
Surgery
Immunosuppresants
Diet Modifications
Thrombo-embolic events
Arrhythmias
What is Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disease.
It is defined by an increase in left ventricular wall thickness that is not solely explained by abnormal loading conditions. - often asymmetrical and occurs in the absence of obvious hypertrophic stimulo
Which area of the heart is most commonly impacted by hypertrophic cardiomyopathy?
Interventricular septum - results in an obstruction of flow thorough the left ventricular outflow tract
Describe the abnormal pathology associated with hypertrophic cardiomyopathy?
Most patients with HCM have abnormal diastolic function, which impairs ventricular filling and increases filling pressure, despite a normal or small ventricular cavity.
What is the presentation of a patient with hypertrophic cardiomyopathy?
Galllop
Syncope
Presyncope
Dizziness
Palpitations
Angina
Ejection Systolic Murmur
Why is it important to measure Haemoglobin levels in hypertrophic cardiomyopathy?
Anemia exacerbates chest pain and dyspnea
What happens to troponin T and BNP levels in hypertrophic cardiomyopathy?
Brain natriuretic peptide (BNP), troponin T levels: Elevated BNP, NT-proBNP, and troponin T levels are associated with a higher risk of cardiovascular events, heart failure, and death
What are the first line treatments for HCM?
B blocker - if side effects then verapamil
What is the diagnosis of Restrictive cardiomyopathy based on?
Establishing the presence of a restrictive ventricular filling pattern
What is restrictive CM characterised by?
diastolic dysfunction with restrictive ventricular physiology, whereas systolic function often remains normal. atrial enlargement occurs due to impaired ventricular filling during diastole, but the volume and wall thickness of the ventricles are usually normal.
What causes increased stiffness of the myocardium?
deposition of abnormal substances (ie, amyloid proteins, noncaseating granulomas, iron) within the heart tissue = leads to diastolic dysfunction
What is the result of restrictive cariomyopathy?
Patients typically have reduced compliance (increased diastolic stiffness), and the left ventricle cannot fill adequately at normal filling pressures
Reduced left ventricular filling volume leads to a reduced cardiac output.
What might someone with restrictive CM uniquely present with?
comfortable in the sitting position because of fluid in the abdomen or lungs, and they frequently have ascites and pitting edema of the lower extremities.
Enlarged liver
Weight loss
What investigations should be conducted for someone with suspected Restrictive CM?
FBC, Serology, Amylodosis check, Chest Xray ,ECG
What clinical symptoms would be suggestive of amyloidosis?
Easy bruising, periorbital purpura, macroglossia, and other systemic findings, such as carpal tunnel syndrome, should be an indication for the clinician to consider amyloidosis.
How is Restrictive Cardiomyopathy treated>
Heart Failure Medication - ACE Inhibitors, ARBs, Diuretics
Immunosuppression - steroids
Pacemaker
Antiarrhythmic Therapy
2.What structural change of the heart is most commonly associated with aortic stenosis?
Left ventricular hypertrophy
Which type of cardiomyopathy is associated with sudden cardiac death in athletes?
Hypertrophic cardiomyopathy
What are the two main major Duke’s criteria for diagnosing infective endocarditis?
- Positive blood culture for typical micro-organisms
- ECHO showing valvular regurgitations
What are the 6 minor Dukes Criteria for diagnosis of Infective Endocarditis?
- Predisposing cardiac lesion
- Intravenous drug use
- Temperature >38
- Embolic phenomena
- Immunologic phenomena
- Positive blood culture which doesn’t meet the main criteria organisms
what is meant by regional blood vasodilation?
Increased muscle activity -> Increase oxygen demand -> increased demand is met by increasing blood flow to exercising muscle
How is muscle vasodilation achieved?
Vasoactive substrates and products of muscle metabolism, eg.CO2, lactate, hydrogen peroxide and potassium ions
Vasoactive mediators released by the endothelium, eg. nitric oxide (NO),ATP, adenosine, prostaglandins
β-2 adrenoceptor activation
