EHR519 Lecture Notes - Lecture 2: Mitral Valve Stenosis, Aortic Stenosis, Pulmonary Valve Stenosis
1. Week 2: CVD – Pathophysiology of Cardiovascular
Disease: Heart Mechanisms (Part B)
Rheumatic Heart Disease
Acute Rheumatic Fever
Acute rheumatic fever (ARF) is an illness involving a reaction to a bacterial infection with Group A
streptococcus (GAS infection)
ARF induces an acute generalized (i.e. whole body) inflammatory response which mainly affect the heart,
brain and skin
Usually present unwell with significant joint pain
Following recovery from ARF, there are usually no deleterious effects to rain, joints or skin
However, there is often persisting/permanent damage to the mitral and aortic valves of the heart
known as rheumatic heart disease (RHD)
ARF elicits greater cumulative damage to the heart valves and consequent RHD due to frequent
occurrence of ARF episodes
Stage 1: GAS infection – 1-3 weeks after initial GAS infection susceptibility to developing ARF
common in children aged 5-14 still occurs in adults
Stage 2: ARF – untreated GAS infection (usually pharyngeal) may lead to ARF
Stage 3: Recurrent ARF – multiple episodes of ARF (stage 2) progressive damage to the mitral
and aortic valves
Stage 4: RHD – multiple episodes of recurrent ARF RHD due to significant dysfunction of the
affected heart valves
Globally, ARF is the most common cause of adolescent cardiac disease and subsequent CVD mortality in
children, adolescents and adults <40 years
Australia: GAS infection, ARF and RHD more of an issue in Indigenous Australians in rural and remote
areas
Heart Valve Disease
Aortic Valve Stenosis
Most common and serious valve disease involving narrowing of the valve opening which restricts blood
flow from the left ventricle to the aorta
Can be of congenital origin (“bicuspid” valve), and can also develop late in life-span due to calcification
and scarring progression usually begins after 60 and become notable at 70-80 years
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Many people do not experience any symptomology until blood flow restriction becomes significantly
reduced
Symptoms include: breathless, angina, syncope (fainting), palpitations, decreased activity, notable fatigue
Infants and children: fatigue upon exertion, lack of weight gain, breathing problems
May lead to heart failure in cases where the thickened wall/valve cusps protrude into the ventricle thus
limiting end diastolic volume (EDV) and subsequent stroke volume (SV)
Mitral Valve Stenosis
Like aortic valve stenosis, mitral valve stenosis involves narrowing of the valve opening and restriction of
blood flow, however, this is from the left atria to the left ventricle
Almost always occurs in response to multiple episodes of ARF – in other words, mitral valve disease can
essentially be thought of as RHD
Mitral valve stenosis needs to be confirmed other similar resenting pathophysiology’s
Myxoma: a cancerous tumour in the left atria which restricts atria-to-ventricle blood flow
A proximal (to the LA) blood clot that reduces flow through the mitral valve (can be from
thrombosis/embolus)
Mitral valve stenosis lack of blood flow leaving the atria atrial and thus pulmonary vein congestion
can provide congestive pressure all the way back to the right atria and ventricle
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Tricuspid Valve Stenosis
Tricuspid aortic stenosis involves narrowing of the tricuspid valve opening, restricting blood flow between
the right atria and right ventricle
Chronic effects include right atrial enlargement (hypertrophy) due to atrial flow congestion, and can
further result in atrophy of the right ventricle due to insufficient filling at EDV
Rheumatic fever, ineffective endocarditis, tumours, congenital birth defects
Symptoms are usually mild in nature, but include: palpitations, a fluttering discomfort in the chest, cold
skin and fatigue (insufficient cardiac output)
Right atrial retrograde also magnifies right atrial enlargement enlarged P-wave in ECG leads
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Week 2: cvd pathophysiology of cardiovascular. Acute rheumatic fever (arf) is an illness involving a reaction to a bacterial infection with group a streptococcus (gas infection) Arf induces an acute generalized (i. e. whole body) inflammatory response which mainly affect the heart, brain and skin. Usually present unwell with significant joint pain. Following recovery from arf, there are usually no deleterious effects to rain, joints or skin. However, there is often persisting/permanent damage to the mitral and aortic valves of the heart known as rheumatic heart disease (rhd) Arf elicits greater cumulative damage to the heart valves and consequent rhd due to frequent occurrence of arf episodes. Stage 1: gas infection 1-3 weeks after initial gas infection susceptibility to developing arf common in children aged 5-14 still occurs in adults. Stage 2: arf untreated gas infection (usually pharyngeal) may lead to arf. Stage 3: recurrent arf multiple episodes of arf (stage 2) progressive damage to the mitral and aortic valves.
