Structural Heart Disease Flashcards
How do you calculate stroke volume?
End Systolic volume - End diastolic volume
When do structural heart diseases happen?
Some are congenital
Some form later in life
What are congenital causes of structural heart disease? (6)
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 causes of SHD that develop later in life?
can be due to valvular dysfunctions (Atrial stenosis /regurgitation) or muscular (cardiomyopathies)
What is a ventricular septal defect?
Wall between 2 ventricles fails to develop in fetus- hole in the wall
You get a mixture in oxygenated and deoxygenated blood
Symptoms: Trouble gaining weight, poor feeding, palpitations
Sometimes the hole closes with age
Treatment: Open heart surgery- catheterisation
What is tetralogy of fallot?
These 4 conditions happen together:
- ventricular septal defect
- Pulmonary stenosis
- Widening of aortic valve- sits on L and R ventricle allowing mixing of blood
- Right ventricle hypertrophy- thickening of RV wall
What is atrial septal defect?
Wall between 2 aortas fails to develop
What is coarctation of the aorta?
Narrowing of the aorta
Ventricle has to work harder to push blood- can lead to thickening of the heart wall
hHat are valvular defects which can affect the heart?
Aortic Stenosis
Aortic Regurgitation
Mitral Stenosis
Mitral Regurgitation
What is the biggest cardiac cause of problems that can later lead to heart disease?
What is its epidemiology (M/F, Age?)
Rheumatic heart disease
More prevalent in females
Greatest in 25-49
What is the epidemiology of calcific aortic valve disease?
Affects M and F same
Most common >/= 80yrs
What is the epidemiology of degenerative mitral valve disease
More prevalent in F
Affects >/=80 yrs most
How does prevalence of mitral regurgitation change with age?
Dramatically increases in prevalence with increasing age
What is the aetiology of aortic stenosis
most common valvular disease in the US and Europe requiring treatment (second most frequent cause for cardiac surgery)
Largely affects seventh or eighth decade of life
What is aortic stenosis preceded by?
aortic sclerosis (aortic valve thickening without flow limitation)
How is aortic stenosis often suspected?
presence of an early-peaking, systolic ejection murmur, and confirmed by echocardiography.
What are risk factors of aortic stenosis? (8)
Hypertension HighLDL (low density lipoprotein cholesterol) levels Smoking Elevated C-reactive protein Congenital bicuspid valves Chronic Kidney Disease Radiotherapy Older age
What are causes of atrial stenosis?
Rheumatic heart disease
Congenital heart disease
Calcium build up
What is the pathophysiology behind aortic stenosis?
Long-standing pressure overload -> left ventricular hypertrophy (LVH).
Ventricle maintains a normal wall stress (afterload) despite pressure overload produced by stenosis but as the stenosis worsens, the adaptive mechanism fails and left ventricular wall stress increases.
Systolic function declines as wall stress increases -> systolic heart failure.
What is the history and presentation of someone with aortic stenosis?
Exertional dyspnoea and fatigue
Chest pain
Ejection systolic murmur
H/O Rheumatic fever, high lipoprotein, high LDL, CKD, age >65
What investigation would you carry of to diagnose atrial stenosis?
Transthoracic echocardiography
ECG Chest X ray (LVH)
Cardiac catheterisation
Cardiac MRI
How is aortic stenosis managed?
Aortic valve replacement is primary treatment of symptomatic AS and asymptomatic severe AS in patients with LVEF <50% or undergoing other cardiac surgery
AVR may be considered in asymptomatic with V severe AS/severe AS with rapid progression/ abnormal exercise test/ elevated serum BNP levels
Other treatment: Balloon aortic valvuloplasty Antihypertensive ACE inhibitors Statins
What is the aetiology of aortic regurgitation?
It’s 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
Not as common as AS or MR
What is the onset of aortic regurgitation?
Can be chronic -> lead to congestive cardiac failure
Can be acute -> medical emergency, presenting with sudden onset of pulmonary oedema and hypotension or cardiogenic shock
What are congenital and acquired cause of aortic regurgitation?
Rheumatic heart disease Infective endocarditis Aortic valve stenosis Congenital heart defects Congenital bicuspid valves
What are aortic root dilation causes of aortic regurgitation?
Marfan’s Syndrome
Connective tissue disease/collagen vascular diseases
Ankylosing spondilytis
Traumatic
What is the pathophysiology behind acute aortic regurgitation?
- 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
What is the pathophysiology behind chronic aortic regurgitation?
- gradually increase in LV volume
- LV enlargement and eccentric hypertrophy
Early stages:
- Ejection fraction normal or slightly increase
- after some time Ejection fraction falls and LV end systolic volume rises
Eventually:
- LV dyspnoea
- lower coronary perfusion
- ischemia, necrosis and apoptosis
What is the history and presentation of aortic regurgitation?
Acute AR: Cardiogenic shock Tachycardia Cyanosis Pulmonary edema Austin flint murmur
Chronic AR:
Wide pulse pressure
Corrigan (water hammer pulse)
Pistol shot pulse (Traube sign)
What investigations would we carry out to diagnose aortic regurgitation?
Transthoracic echocardiography
Chest X ray
Cardiac catheterisation
Cardiac MRI/CT Scan
How is acute aortic regurgitation managed?
Ionotropes/vasodilators & valve replacement & repair
How is chronic aortic regurgitation managed?
Chronic asymptomatic:
If LV function is normal can be managed by drugs or reassurance
Chronic symptomatic:
First line is valve replacement with adjunct vasodilator therapy
How is aortic regurgitation prevented?
Prevention is key: Treat Rheumatic fever and infective endocarditis.
What is the aetiology of mitral stenosis?
Obstruction to left ventricular inflow at the level of mitral valve due to structural abnormality of the mitral valve
Rheumatic fever is the main cause ( in developing countries)
As disease progresses it leads to pulmonary hypertension and right heart failure occurs
What are causes of mitral stenosis?
Rheumatic fever Amyloidosis Carcinoid syndrome Rheumatoid arthritis Use of ergot/serotonergic drugs Whipple disease SLE Congenital deformity of the valve Mitral annular calcification due to aging
What is the pathophysiology behind mitral stenosis? (5)
Initially moderate exercise or tachycardia result in exertional dyspnoea due to increased left atrial pressure
Severe mitral stenosis leads to increase in left atrial pressure , transudation of fluid into the lung interstitium leading to dyspnoea at rest or exertion
Pulmonary hypertension may develop as the result of it
The restricted orifice limits filling of left ventricle limiting cardiac output
Hemoptysis if bronchial vein rupture
What is the history and presentation of mitral stenosis?
H/0 of Rheumatic fever Dyspnoea orthopnoea Diastolic murmur Loud P2 Neck vein distention Hemoptysis 40-50 years age
What investigations would we carry out for someone with mitral stenosis?
ECG Transthoracic echocardiography Chest X ray Cardiac catheterisation Cardiac MRI/CT Scan
How is mitral stenosis managed?
Progressive asymptomatic:
No therapy required
Severe asymptomatic:
No therapy generally required adjuvant balloon valvotomy
Severe symptomatic:
diuretic, balloon valvotomy, valve replacement & repair adjunct b blockers
What technologies already exist and are under development to surgically treat aortic stenosis?
Currently:
Minimally invasive surgical (sutureless)
Transcatheter aortic valve implantation device
Under development:
Flexible polymeric valve
Tissue- engineered heart valve
What are causes of acute mitral regurgitation?
Mitral valve prolapse Rheumatic heart disease Infective endocarditis Following valvular surgery Prosthetic mitral valve dysfunction
What are causes of chronic mitral regurgitation?
Rheumatic heart disease SLE Scleroderma Hypertrophic cardiomyopathy Drug related
What is the pathophysiology behind mitral regurgitation?
Leakage of blood from left ventricle to left atrium due to mitral valve stenosis
Chronic MR:
- 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
- a decrease in end-systolic volume
Eventually prolonged volume overload leads to left ventricular dysfunction and increased left ventricular end-systolic diameter
What is the history and presentation of mitral regurgitation?
Dyspnea diminished S1 Murmur high pitched blowing xx Fatigue Orthopnea Chest pain Atrial fibrillation
What investigation would you carry out to diagnose mitral regurgitation?
ECG Transthoracic echocardiography Chest X ray Cardiac catheterisation Cardiac MRI/CT Scan
How is mitral regurgitation managed?
Acute MR :
Emergency Surgery adjunct preoperative diuretics adjunct intra-aortic balloon counterpulsation
Chronic asymptomatic:
1st ACE inhibitors
Beta blockers if left ventricular ejection fraction is less than 60%
1st line is surgery
Chronic symptomatic:
1st surgery plus medical treatment
If left ventricular ejection fraction is less than 30% 1st line is Intra-aortic balloon counterpulsation
What are the main types of muscular cardiomyopathies?
Dilated
Hypertrophic
Restrictive
What is a cardiomyopathy and what can it lead to?
Cardiomyopathy is a disease of the heart muscle that makes it harder for heart to pump blood to rest of your body
Can lead to heart failure
What is the aetiology of dilated cardiomyopathy?
One of the most common causes of heart failure
Mostly occurs in 3rd or 4th decade
Progressive, usually irreversible causing global systolic dysfunction with heart failure
What are familial/primary causes of dilated cardiomyopathy?
Primary without family history - idiopathic
What are secondary causes of dilated cardiomyopathy?
Heart valve disease After childbirth Thyroid disease Myocarditis Alcoholism Autoimmune disorders Ingestion of drugs Mitochondrial disorders
What is the pathophysiology behind dilated cardiomyopathy?
Enlargement of the left ventricle
Lower ejection fraction and increase in the ventricular wall stress and end systolic volumes.
Early compensatory mechanisms include:
- An increase in heart rate and tone of the peripheral vascular system.
- Neurohumoral activation of the renin-angiotensin aldosterone system and an increase in circulating levels of catecholamines.
- Levels of natriuretic peptides are also increased.
Eventually these compensatory mechanisms become overwhelmed and the heart fails.
How does dilated cardiomyopathy present?
Dyspnoea, displaced apex beat, S3 or systolic murmur fatigue, angina, pulmonary congestion low cardiac output
What are investigations for dilated cardiomyopathy?
Genetic Testing Viral serology ECG Chest X ray Cardiac catheterisation Cardiac MRI/CT Scan Exercise stress test Echocardiography
How is dilated cardiomyopathy managed?
- Counselling
- Diet modifications - fluids and Na restriction
- Treat underlying disease- immunosuppressants for sarcoidosis and myocarditis phlebotomy for haemochromatosis
- Treat symptoms of heart failure- ACEi, B blockers, diuretics, angiotensin 2 receptor antags. (lower dose of AXWi if patient gets cough, hypertension or renal dysfunction). If meds ineffective: surgery (LVAD and transplant) or LVAD and optimise medical treatment
- Antiarrhythmics- amiodarone, dofetilide or ICD/CRT
- Thromboembolic events- Anticoagulants (warfarin)
What is the aetiology of hypertrophic cardiomyopathy?
A genetic CVR disease- autosomal dominant in 50% of cases
Its an increase increase in left ventricular wall thickness that is not solely explained by abnormal loading conditions.
It’s the leading cause of sudden cardiac death in preadolescent and adolescent children.
Most patients are asymptomatic. First manifestation may be sudden death
What is the pathophysiology behind hypertrophic cardiomyopathy?
Hallmarks: inappropriate, often asymmetrical and occurs in absence of hypertrophy stimulus
Hypertrophy can occur in any region of LV but often in interventricular septum leading to obstructed flow in LV outflow tract
Most with HCM have abnormal diastolic function, which impairs ventricular filling and increases filling pressure, despite a normal or small ventricular cavity.
These patients have abnormal calcium kinetics and subendocardial ischemia, which are related to the profound hypertrophy and myopathic process.
What is the history and presentation of hypertrophic cardiomyopathy?
Sudden cardiac death Double carotid artery impulse, S3 gallop
Syncope ejection systolic murmur
Presyncope
Congestive heart failure
Dizziness
Palpitations
Angina
What are investigation to diagnose hypertrophic cardiomyopathy?
Hemoglobin level: Anemia exacerbates chest pain and dyspnea
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
Echocardiography
Chest Xray
Cardiac MRI
What is management for hypertrophic cardiomyopathy (with symptoms)?
B blocker (if s/e give verapamil) If symptoms persist add disopyramide For refractory symptoms: mechanical therapy - pacemaker with short AV delay OR septal myectomy or ablation (only if no contraindications to more invasive treatment)
What is the aetiology behind restrictive cardiomyopathy?
Diagnosis based on establishing presence of restrictive ventricular filling pattern so less well defined.
It is characterized 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 is the epidemiology of restrictive cardiomyopathy?
Accounts for 5% of diagnosed cardiomyopathies
What are causes of restrictive cardiomyopathy?
Idiopathic
Familial (has been related to troponin I or desmin mutations, the latter often in association with a skeletal myopathy)
Associated with various systemic disorders, such as haemochromatosis, amyloidosis, sarcoidosis, Fabry’s disease, carcinoid syndrome, scleroderma, anthracycline toxicity.
Previous radiation.
What is the pathophysiology behind restrictive cardiomyopathy?
Increased stiffness of the myocardium
Infiltrative cardiomyopathies are characterized by deposition of abnormal substances (ie, amyloid proteins, noncaseating granulomas, iron) within the heart tissue.
Infiltration causes the ventricular walls to stiffen, leading to diastolic dysfunction.
Restrictive physiology predominates in the early stages, causing conduction abnormalities and diastolic heart failure.
Adverse remodelling may lead to systolic dysfunction and ventricular arrhythmias in advanced cases.
What abnormal physiology do patients with restrictive cardiomyopathy have?
Increased stiffness of the myocardium causes ventricular pressures to rise steeply with small increases in volume.
Thus, accentuated filling occurs in early diastole and terminates abruptly at the end of the rapid filling phase.
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 is the history and presentation for restrictive cardiomyopathy?
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.
The liver is usually enlarged and full of fluid, which may be painful.
Weight loss and cardiac cachexia.
Easy bruising, periorbital purpura, macroglossia, and other systemic findings, such as carpal tunnel syndrome- consider amyloidosis.
Increased jugular venous pressure is present.
The pulse volume is decreased, consistent with decreased stroke volume and cardiac output.
What are investigations to diagnose restrictive cardiomyopathy?
CBC Serology Amylodosis check Chest Xray ECG Echocardiography Catheterisation MRI/Biopsy
How is restrictive cardiomyopathy managed?
Heart failure medication:
Angiotensin-converting enzyme inhibitors or angiotensin receptor II blockers
If pt has reduced LV: diuretics and aldosterone inhibitors in addition
Antiarrhythmic Therapy
Immunosuppression- Steroids
Pacemaker
Cardiac transplantation
