Cardio - Structural Heart Disease Flashcards
What are the three layers of heart tissue?
Epicardium (layer of epithelial cells)
Myocardium (muscular layer)
Endocardium (layer of endothelial cells)
What are the 2 main phases of the cardiac cycle?
Systole - ventricles contract
Diastole - ventricles relaxed
What happens to the cardiac cycle in structural heart disease
In structural heart disease, there is a disruption of the cardiac cycle and thus less stroke volume possibly leading to heart failure.
What are the 3 main phases of systole?
Isovolumetric contraction, rapid ejection, reduced ejection
What are the 4 main stages of diastole?
Atrial systole
Isovolumetric relaxation
Rapid passive filling
Slow passive filling
What happens in atrial systole?
The atria contract to top up the blood filling the ventricles, which primarily occurred during the rapid and reduced passive filling.
How much does atrial systole contribute to ventricular filling?
10-40% - it is higher when there is a reduced diastolic window such as during exercise
What does atrial systole correlate with on the ECG?
P wave
What sound may be heard in atrial systole?
S4 sound
What does s4 sound represent?
Sometimes if the ventricles are already full, atria contracting to eject blood into them leads to back flow into the atria therefore an abnormal sound. This can occur in congestive heart failure, tricuspid incompetence or pulmonary embolism.
What happens in isovolumetric contraction?
The AV valves close when the ventricular pressure exceeds the atrial pressure, and the ventricles start contracting. The semilunar valves may not be open yet therefore volume in the ventricles is fixed.
What does isovolumetric contraction correlate with on ECG?
QRS complex
What sound do we hear in isovolumetric contraction?
S1 sound - lub - caused by mitral valve closing
What is rapid ejection?
When ventricular pressure exceeds the pressure in the aorta or pulmonary artery, then the semilunar valves open and blood is forced out into the ventricles at a rapid rate
What is reduced ejection?
This is ventricular repolarisation with a decline in ventricular active tension leading to a fall in the pressure gradient
What does reduced ejection correlate with on the ECG?
T wave
What is isovolumetric relaxation?
Semilunar valves shut but the AV valves remain open until ventricular pressure falls below atrial pressure
What sound do we hear in isovolumetric relaxation?
S2 - dub on semilunar valves closing
What is rapid passive filling?
As ventricles continue to relax, ventricular pressure eventually falls below atrial pressure causing the AV valves to open - meaning that blood can start filling the ventricles again
What heart sound may we hear during rapid passive filling?
S3
What does s3 represent?
Turbulent ventricular filling possibly due to severe hypertension or mitral incompetence. May be normal in athletes or pregnant women
What is another name for reduced passive filling?
Diastasis
What is reduced passive filling?
Ventricular volume rises more slowly without the help of the atria
What is ESV?
End systolic volume
What is EDV?
End diastolic volume
How do we calculate stroke volume?
EDV - ESV
When can we get structural heart defects?
They can be congenital or develop later in life
What are some examples of congenital heart diseases? (6)
Atrial septal defect (ASD) Ventricular septal defect (VSD) Coarctation of the aorta Patent foramen ovale (PFO) Patent Ductus Arteriosus (PDA) Tetralogy of Fallot (TOF)
What are some examples of structural heart diseases developing later in life?
Cardiomyopathies
What happens in VSD?
Interventricular septum doesn’t develop properly and we may get mixing of oxygenated and deoxygenated blood
What are the clinical signs of VSD?
Poor weight gain
Poor feeding
Palpitations
How can VSD be cured/treated?
Hole may close up itself or open heart surgery or cardiac catheterisation
What does tetralogy of fallout include?
Widening of the aorta
Pulmonary stenosis
VSD
Right ventricular hypertrophy
What does widening of the aorta (TOF) cause?
Causes some mixing or diversion of the blood from the right ventricle into the aorta
Why and how do we correct right ventricular hypertrophy?
Critical defect - surgery is needed to correct abnormal breathing
What happens in ASD?
Atrial wall fails to develop properly
What is coarctation of the aorta?
This is narrowing of the aorta e.g. in the descending aorta
What may result from coarctation of the aorta?
Blood struggles to get through, therefore we may get LVH and eventually heart failure
What is rheumatic heart disease?
Scarring or inflammation of the heart which results from rheumatic fever. It is the most common cause of problems leading to valvular heart disease in developing countries
What is calcific aortic disease?
Aortic valve is calcified
What is degenerative mitral valve disease?
Degeneration of the mitral valve due to age or other problems, more commonly affecting males
Risk factors aortic stenosis?
Old age Hypertension LDL Increased CRP Radiotherapy Congenital Bicuspid Valves Chronic Kidney Disease
Causes of aortic stenosis?
Rheumatic heart disease
Congenital hearth disease
Calcium build up
What precedes AS?
Aortic sclerosis - we don’t notice it
How does AS develop?
Valvular endothelium is damaged due to abnormal blood flow across the valve, starting from an unknown trigger. This causes an inflammatory process and therefore fibrosis, calcium deposition and eventually low valve motility
What is the consequence of AS?
Long standing pressure overload
LVH
Ventricles try to maintain wall stress despite pressure overload, however eventually the wall stress increases thus reducing systolic function and leading to systolic heart failure
Presentation of AS?
Exertional dyspnoea
Fatigue
Chest pain
Ejection systolic murmur radiating to carotid
AS Investigations?
Transthoracic echo
ECG
Cardiac catheterisation
Cardiac MRI
AS Management?
Aortic Valve replacement
Antihypertensives
ACEis
Statins
What is aortic regurgitation?
Diastolic leakage of the blood from the aorta into the left ventricle due to incompetence from valve leaflets, arising from valve disease or dilation of the aortic root
What causes AR?
Rheumatic heart disease Infective endocarditis Aortic valve stenosis Congenital heart defects Congenital biscuspid valves
What are causes of aortic root dilation in AR?
Marfan’s
Connective tissue diseases
Ankylosing spondylitis
Trauma
What can acute AR lead to?
Cardiogenic shock
What can chronic AR lead to?
Congestive heart failure
What is the presentation of Acute AR?
Cardiogenic shock Tachycardia Cyanosis Pulmonary oedema Austin flint murmur
What is the presentation of chronic AR?
Wide pulse pressure
Corrigan wate hammer poulse
Pistol shot pulse
What investigations do we do for AR?
Echo
CXR
Cardiac catheterisation
Cardiac MRI
How do we manage AR?
Aortic valve replacement or vasodilator therapy - prevention of rheumatic fever or infective endocarditis is key
What is mitral stenosis?
Obstruction to left ventricular inflow at the level of the mitral valve to to sutrcutral abnormality of the mitral valve
What are the causes of Mitral stenosis?
Rheumatic fever Carcinoid syndrome SLE Mitral annular calcification due to ageing Rheumatoid arthritis Congenital
What can mitral stenosis lead to?
Pulmonary hypertension and right sided heart failure
Mitral stenosis presentation?
Haemoptysis
Orthopnoea
Diastolic murmur
Neck vein distension
Mitral stenosis management?
Adjuvant balloon valvotomomy, valve replacement and repair adjunct beta blockers if severe or symptomatic
Mitral stenosis investigations?
ECG Echo CXR Cardiac catheterisation Cardiac MRI/CT
What is mitral regurgitation?
Abnormal several of blood from the left ventricle to the left atrium during systole due to damaged leaflets
What causes acute MR?
Mitral valve prolapse Rheumatic heart disease Infective endocarditis Post valvular surgery Prosthetic mitral valve dysfunction
What causes chronic MR?
Rheumatic heart disease SLE Scleroderma Hypertrophic cardiomyopathy Drug related
What happens in MR?
Progression of chronic MR cuases eccentric hypertrophy thus we get elongation of the myocardial fibres. This causes an increase in EDV and preload and a fall in after load. This leads to left ventricular overload this we get dysfunction and heart failure later on in life
MR Presentation?
Dyspnoea Murmur high Fatigue Orthopnoea Chest pain Atrial fibrillation Diminished S1 Pitched, blowing
MR Investigations?
ECG Echo CXR Cardiac MRI/CT Cardiac catheterisation
MR Management?
Emergency surgery if acute or chronic symptomatic along withe medical treatment, ACEis if chronic asymptomatic
What are cardiomyopathies?
Disease of the heart muscle making it harder for the heart to pump blood to the rest of the body, thus potentially leading to heart failure
Main types of cardiomyopathy?
Dilated
Hypertrophic
Restrictive
What are the causes of dilated cardiomyopathy?
Familial Heart valve disease After child brith Thyroid disease Myocarditis Alcoholism Autoimmune Ingestion of drugs Mitochondrial disorders
What happens in DCM?
Ventricular chamber enlargement and systolic dysfunction with normal left ventricular wall thickness - leads to lower EF and increase in ventricular wall stress and ESV. We get an increase in HR and TPR. Overconpensation leads to heart failure
DCM Presentation?
Dyspnoea Murmur Fatigue Angina Pulmonary congestion Low cardiac output Displaced apex beat due to LVH
DCM Investigations?
Genetic testing Viral serology ECG CXR Cardiac catheterisation MRI/CT Exercise stress test Echo
DCM Management?
Lifestyle modifications, medicine if ineffective
Treat underlying cause
What is hypertrophic cardiomyopathy?
Genetic Cardiovascular disease defined by an increase in left ventricular wall thickness that is not solely explained by abnormal loading conditions
What happens in HCM?
Abnormal diastolic function impairs ventricular filling and increases filling pressure, can lead to sudden death
Presentation of HCM?
Sudden cardiac death - common in children S3 gallop Congestive heart failures Syncope Dizziness Palpitations Ejection systolic murmur
Investigations for HCM?
HB levels: anemia exacerbates chest pain and dyspnoea BNP Trops Echo CXR MRI
Management of HCM?
Medications
Pacemaker
Surgery to increase ventricle size
What is restrictive cardiomyopathy?
Diastolic dysfunction with restrictive ventricular physiology, whereas systolic function often remains normal
What causes RCM?
Idiopathic
Familial
Systemic e.g. haemochromatosis
What happens in RCM?
Increased stiffness of myocardium causes ventricular pressures to rise lots with small increases in volume, reduced cardiac output
What is the presentation of RCM?
Fluid or oedema Liver enlargement Weight loss Easy bruising Pulse volume decreased
What is the investigations in RCM?
CBC Serology Amyloidosis check CXR ECG Echo Catheterisation MRI/Biopsy
What is the management in RCM?
Heart failure medications Antiarrhythmic therapy Immunosuppression - steroids Pacemaker Cardiac transplantation (last resort)
