Physiology of rheumatic heart disease
Physiology of rheumatic heart disease
This video provides an overview of how RHD affects the heart and is part 3 of the Introduction to Acute Rheumatic Fever and Rheumatic Heart Disease and part 2 of the Administering Bicillin online learning modules. https://www.rhdaustralia.org.au/e-lea…
This video provides an overview of how RHD affects the heart. The learning objective is to:
- describe the changes in the heart that define rheumatic heart disease.
More information on this topic can be found in the Diagnosis of rheumatic heart disease chapter in the 2020 Australian guideline for prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease, 3rd edition.
Content
5.52 -> To understand why the injections are important
8.24 -> it is useful to know what is happening within
the heart with rheumatic heart disease.
13.44 -> This shows healthy blood flow through the
different chambers of the heart. Blood flowing
18.24 -> through healthy valves moves without restriction
through the four chambers of the heart. There are
23.52 -> four valves - the mitral valve between the
left atrium and ventricle - the tricuspid
28.64 -> valve between the right atrium and ventricle
- the aortic valve, and the pulmonary valve.
35.68 -> Each valve is made up of leaflets that separate
fully to allow smooth blood flow and then close
41.04 -> tightly together to prevent backflow. This ensures
that the blood circulates in one direction.
47.6 -> In some people the body's autoimmune response
to a Group A Streptococcal or GAS infection
52.8 -> causes inflammation. This is ARF and can
include inflammation of the heart which is
58.24 -> called carditis. The heart valves may also
become inflamed which causes stretching and
63.76 -> thickening of the valve leaflets. When the cardiac
resolves some valve leaflets may remain scarred
70.48 -> stiff and immobile or stretched.
This is rheumatic heart disease.
75.36 -> The valves predominantly affected in RHD are
those on the left side of the heart - the mitral
80.48 -> and aortic valves. There are two conditions of the
heart valves in RHD - regurgitation and stenosis.
88.56 -> With valvular regurgitation the stretched leaflets
have not regained shape and therefore do not close
94.16 -> completely. This causes blood to leak backwards
regurgitation is also referred to as insufficiency
100.8 -> or a leaky valve. With valvular stenosis the
stretch leaflets have remained thickened and stiff
107.28 -> and the opening is narrowed reducing the amount
of blood that can flow through. If the narrowing
112.72 -> is mild the overall functioning of the heart
may not be reduced. However, in severe stenosis
118.56 -> blood can back up and pull in the chambers
preventing adequate blood flows through the body.
124.32 -> Blood pooling in the chambers
has a greater tendency to clot
127.84 -> increasing the risk of a
stroke or pulmonary embolism.
132 -> Regurgitation usually happens early in the
disease; stenosis later in the disease process.
138.96 -> It is possible to have both stenosis and
regurgitation in one or more heart valves
144 -> at the same time. And valves do not have smooth
contours are more likely to become infected.
150.64 -> As valve damage progresses the heart has to
work harder to circulate the right amount of
155.44 -> blood through the body. In severe cases the
heart muscle enlarges and thickens thereby
162 -> losing elasticity and efficiency. It is common
for people with RHD to develop heart failure.
Source: https://www.youtube.com/watch?v=JSuCM87lpNY