WEEK 10 Flashcards
Understand the genetics and molecular pathology of congenital heart disease.
This can include conditions like:
- ventricular septal defects,
- atrial septal defects,
Understand the importance of single gene, chromosomal and microdeletion syndromes.
Single gene disorders occur when mutations take place in the DNA sequence of a single gene. Examples:
- Marfan syndrome (💭 LINCON!! - Tall, slender, long face)
- Fibrillin 1 gene
- autosomal dominant
- tendency to develop aortic anneurysms
Chromosomal syndromes occur when there are missing or additional chromosomes, or when there are alterations to the structure of the chromosomes.
- Down syndrome
- Trisomy 21
- Atrioventricular septal defect
Understand the pathophysiology and natural history of MITRAL STENOSIS
- Atrium - ventricle pressure gradient increases
- Left atrial pressure increases
- Pulmonary venous and capillary pressures increase
- Pulmonary vascular resistance increases
- Pulmonary artery pressure increases and pulmonary hypertension develops
- Right heart dilatation with tricuspid regurgitation and pulmonary regurgitation
- LEFT VENTRICLE pressures and systolic function normal
Describe the common clinical features of MITRAL STENOSIS
- Dyspnoea: mild exertion to pulmonary oedema
- Haemoptisis: rupture of thin walled veins
- Systemic embolisation: Left atrium and left atrial appendage enlargement
- Infective endocarditis
- Chest pain
- Hoareness
List the diagnostic investigations appropriate for MITRAL STENOSIS
- Mitral facies
- Pulse: normal
- JVP: prominent a wave
- Tapping apex beat and diastolic thrill
- RV heave
- Auscultation
- ECG: P wave >0.12sec
- CXR: LA enlargement
- Echocardiogram: thickening and scarring of the leaflets
Understand the pathophysiology and natural history of MITRAL REGURGITATION
- Effective resurgent orifice: not fixed which is dependent on:
- Preload
- Afterload
- Left ventricle contractility
- Left ventricle compensation
- Acute: End systolic pressure increases and end systolic volume decreases
- Chronic: End diastolic volume increases and end systolic volume returns to normal
Describe the common clinical features of MITRAL REGURGITATION
Acute mitral valve regurgitation
= breathlessness: pulmonary oedema, cardiogenic shock
Chronic mitral valve regurgitation
= fatigue, exhaustion (low cardiac output), right heart failure, dyspnoea or palpitations due to AF
List the diagnostic investigations appropriate for MITRAL REGURGITATION
- Pulse: normal or reduced
- Increased JVP
- Risk and hyperdynamic apex beat
- RV heave
- Auscultation
- ECG - LA enlargement (P wave > 0.12 seconds
- CXR - cardiomegaly, LA enlargement, calcification of mitral annulus
- Echocardiogram - LV dimensions
Understand the pathophysiology and natural history of AORTIC STENOSIS
CAUSED BY EITHER:
- RHEUMATIC HEART DISEASE
- DEGENERATIVE HEART DISEASE
- Increased LV systolic pressure
- Severe concentric hypertrophy and increased LV mass
- Increased LVEDP
- Increased MV02
- Myocardial ischaemia
- LV failure
Describe the common clinical features of AORTIC STENOSIS
- Long asymptomatic phase
- Chest pain (angina)
- Syncope/dizziness
- Breathlessness on exertion
- Heart failure
List the diagnostic investigations appropriate for AORTIC STENOSIS
- Pulse - small volume and slowly rising
- JVP - prominent if RH failure present, low BP
- Vigorous and sustained apex beat
- RV heave
- Auscultation
ECG - LVH voltage criteria, ST/T changes
CXR - calcification of AV
Echocardiogram - demonstrated the AV cusp mobility, LV function and hypertrophy
CMR
Understand the pathophysiology and natural history of AORTIC REGURGITATION
- Increased LVEDV and LV systolic pressure
- LV hypertrophy and LV dilation
- Increased MVO2
- Myocardial ischaemia
- LV failure
Describe the common clinical features of ATRIAL REGURGITATION
ACUTE AR:
- Pulse: large volume and collapsing
- Wide pulse pressure
- Hyperdynamic: displaced apex beat
- Auscultation
CHRONIC AR:
- long asymptomatic phase
- breathlessness on exertion
List the diagnostic investigations appropriate for AORTIC REGURGITATION
ECG - ST/T changes (LV strain), LAD
CXR - cardiomegaly in chronic AR
Echocardiogram - AV cusp, LV function
CMR
Understand the treatment options available as well as their limitations (mitral stenosis/regurgitation, atrial stenosis/regurgitation)
MITRAL STENEOSIS
- Diuretics and restriction of Na intake
- AF: restore sinus rhythm or ventricular rate control
- Anticoagulation: all those with AF, debatable for sinus rhythm
- Valvotomy (balloon vs surgical)
- MVR
MITRAL REGURGITATION
ACUTE MR:
- vasodilators
INTERVENTIONAL TREATMENT
- mitral valve apparatus repair
- mitral valve replacement
ATRIAL STENOSIS
Aortic vavlve replacement or repair
ATRIAL REGURGITATION
Vasodilation therapy
Aortic valve replacement or repair
Describe the medical treatment of infective endocarditis.
The medical treatment of infective endocarditis typically involves a course of high-dose intravenous antibiotics over several weeks. The specific antibiotics used depend on the type of bacteria causing the infection.
List those valvular defects which are amenable to surgery.
- Mitral valve stenosis: This condition occurs when the mitral valve becomes narrow or obstructed. If the stenosis is severe, it can be treated with a surgical procedure called a mitral valvuloplasty or a mitral valve replacement.
- Mitral valve regurgitation: This is a condition where the mitral valve doesn’t close tightly, causing blood to flow backward in the heart. Severe mitral regurgitation can require surgery, either to repair the valve or to replace it.
- Aortic stenosis: A condition where the aortic valve is narrower than normal, limiting blood flow from the heart into the aorta. Severe aortic stenosis can be treated with surgery to replace or repair the valve.
- Aortic regurgitation: This condition occurs when the aortic valve doesn’t close properly, and blood flows back into the heart. Depending on the severity, this condition might require aortic valve repair or replacement surgery.
- Pulmonary valve stenosis: A condition where the pulmonary valve is thickened or narrowed. Surgery can be done to repair or replace the valve.
- Tricuspid valve regurgitation: This is a condition where the tricuspid valve doesn’t close tightly, causing blood to flow backward in the heart. Surgery can be done to repair or replace the valve, especially in cases where the regurgitation is causing right-sided heart failure.
Explain the potential complications of surgery.
- Cardiac tamponade - compression of the heart by an accumpulation of fluid in the pericardial sac
- Death
- Stroke
Describe the surgical techniques available for the treatment of ischaemic heart disease.
Coronary artery bypass grafting (symptomatic and prognostic)
Describe briefly the surgical procedures for the complications of ischaemic heart disease.
Sternotomy
List the types of prosthetic valves in common use.
- Mechanical Valves: Made from materials such as titanium or carbon. They are durable and generally last a lifetime. However, they require the patient to take blood-thinning medications indefinitely to prevent blood clots.
- Tissue Valves: These are made from animal tissue (usually pig or cow) or human tissue (donor heart valves or the patient’s own tissue). These valves can deteriorate over time, and may eventually need to be replaced.
- Transcatheter Valves: These are a newer type of valve that can be inserted through a small incision, often in the leg. They are typically used in patients who are at high risk for traditional open-heart surgery.
- Homografts (or allografts): These are valves taken from a deceased human donor. They are usually used in cases where infection is present or likely.
- Autografts: These valves are taken from the patient’s own body, usually from another part of the heart. This type of valve replacement is less common but may be used in certain situations.
Recognise the most common microorganisms involved.
- Staphyloccus aureus.
- Streptococci (Viridans, gallolyticus)
- Enterococci
Describe the investigations and familiarise with the Modified Duke’s Criteria.
DEFINITE IE =
- 2 major OR 1 major + 3 minor criteria
POSSIBLE IE =
- 1 major + 1 minor OR 3 minor criteria
MAJOR CRITERIA
- blood culture positive for typical microorganism
- echo showing valvular vegetation
MINOR CRITERIA
- Temperature >38C
- IV drug use
- (4 other minor criterias)
Outline the management of infective endocarditis, including the indications for cardiac surgery.
ANTIBIOTIC TREATMENT
- penicillin G
- amoxicillin
- (Flu)cloxacillin or oxacillin
INDICATIONS FOR CARDIAC SURGERY
- Heart failure with valvular dysfunction or cardiac complications
- Uncontrolled infection
~ Persistent fever and positive blood cultures
- Prevention of embolism
~ If the vegetation is persistently large (>10mm).
~ One or more embolic episodes
