Script – RHD Medical Management AV
SLIDE 1
Welcome to RHD Australia’s Health Provider Education series; educational resources for
clinicians by clinicians. RHD Australia is an initiative of James Cook University, Menzies
School of Health Research, and Baker IDI and is supported by the Commonwealth Department
of Health and Ageing.
This module will discuss the management of rheumatic heart disease-related aortic valve
disease. It will also explore the challenges to delivering care in rural and remote settings where
access to specialist and tertiary hospital care can be difficult.
SLIDE 2
This presentation was developed with the assistance of Warren Walsh. Warren is a clinical
cardiologist at the Prince of Wales Hospital in Sydney. He has a longstanding interest in ARF
and RHD, and remote health care delivery. Warren provides regular specialist cardiac outreach
clinics in Central Australia and the Pacific and is past Chairperson of the Indigenous Health
Working Group of the Cardiac Society of Australia and New Zealand.
SLIDE 3
The primary objective of this module is to provide an understanding of the assessment and
management of rheumatic AV valve disease. This includes:
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the nature of the AV lesions and their natural history in the setting of RHD
the appropriate diagnostic investigations and methods used to assess severity
the timing and choice of treatment options
and finally, the major challenges to delivery if care in cross-cultural and remote settings
SLIDE 4
The important take home messages from this module are outlined here.
1. Regular echocardiography and specialist review are essential for ongoing management of
AV valve disease.
2. Early surgical is required for moderate to severe AV valve.
3. We recommend the evidence-based RHD Australia guidelines for the management of RHD,
including AV disease.
4. Good quality primary health care is a key element. Primary health services must be properly
supported in their endeavour to deliver secondary prevention and limit progression of RHD
through antibiotic prophylaxis and regular follow-up.
SLIDE 5
We will use a number of abbreviations in this presentation; let’s define them.
AR is aortic regurgitation, also sometimes known as aortic insufficiency or aortic
incompetence. This is when the AV leaks and blood flows back from the aorta into the LV
during diastole, when LV should only be filling from the LA through the MV.
AS is aortic stenosis. AS is narrowing of the AV and is usually due to formation of scar tissue
in the valve. The narrow valve restricts the normal blood flow from the LV to the aorta.
LVEF stands for left ventricular ejection fraction. This is the proportion of blood in the LV at
the end of diastole that is pumped into the aorta with each contraction.
LVESD is the abbreviation for left ventricular end systolic diameter or the internal diameter of
the LV at the end of its contraction.
NYHA is the abbreviation for the New York Heart Association. The NYHA developed a
classification to assess severity of heart failure according to how short of breath people are.
This gives a score from 1-normal to 4 - severe and disabling shortness of breath.
And finally TTE is the abbreviation for transthoracic echocardiogram, the most commonly
performed echocardiogram, where the ultrasound probe is placed on a patient’s chest.
SLIDE 6
Much of the information presented here is drawn from the Australian Guidelines for the
Prevention, Diagnosis and Management of Acute Rheumatic Fever and Rheumatic Heart
Disease.
These guidelines were substantially updated and revised in 2012 and are available at the RHD
Australia website.
SLIDE 7
A quick reference guide is also available, which provides an excellent summary for busy
clinicians.
SLIDE 8
More information regarding other aspects of the prevention, diagnosis and management of ARF
and RHD can be found at the RHD Australia website in the health provider education modules.
These will be regularly updated and expanded.
SLIDE 9
So let’s move on to assessing and managing rheumatic AV disease. This person is having a
TTE. The availability of portable echocardiography has been a major advance in the diagnosis
and management of people with RHD, especially people living in rural and remote locations.
SLIDE 10
Echocardiography has a key role in the modern management of RHD. So what can we see?
This slide shows the standard TTE views. The lower images are parasternal views; the
ultrasound probe is placed on the left edge of the lower sternum. On the left are parasternal long
axis views showing the lower MV and upper AV and the chamber of the LV on the left - and
the lower LA and upper aortic root on the right.
By rotating the probe 90 degrees the parasternal short axis view is obtained as shown in the
lower two images on the right. The same aspect of the heart is now seen in cross section.
The upper images are obtained with the probe at the apex of the heart; these are called the
apical views. On the left there are two apical four chamber views with the RV on the left and
LV on the right. The smaller chambers are the RA and LA. The line separating the atria and
ventricles is the septum, with the TV on the right and MV on the left.
Finally the upper two images on the right are apical two chamber views that demonstrate the
LV, LA and MV.
SLIDE 11
In RHD the most commonly AV abnormality is AR.
The upper illustration shows a normally functioning AV with the valve leaflets closing
together. This prevents backflow into the LV from the aorta once the heart has finished
contracting. AR can be seen in the lower image. The AV leaflets fail to come together and close
properly and blood leaks back into the LV.
SLIDE 12
AR, even quite severe AR, may be asymptomatic for many years. Symptoms eventually
develop as the regurgitation progresses. Common symptoms are fatigue, increasing shortness of
breath on exertion and at night. These are also the symptoms of heart failure. The worse the
symptoms the worse the outcome.
So, the best approach is to detect AR and monitor it closely – and refer for surgical assessment
before symptoms develop. This can only be done effectively through regular echocardiography
and specialist review. About 1 in 20 people with AR will develop symptomatic disease each
year.
People with AR should be specifically asked if they have fatigue and shortness of breath on
exertion. As disease progresses, people become short of breath occurs at rest when lying flat.
This is called orthopnoea.
SLIDE 13
On physical examination there are signs of a volume overloaded LV. There are peripheral signs
of a hyperdynamic circulation. As the LV struggles to deal with the increased load, it dilates
and the palpable apex beat is displaced laterally towards the axilla.
The murmur is AR typically is typically heard in early diastole and has a blowing quality. It is
best heard at the left sternal border, with the person bending forward, and holding the breath
after breathing out. But it’s often hard to hear, even by the most experienced clinicians.
A systolic flow murmur may be also heard due to the increased forward flow of blood across
the aortic valve. A systolic murmur can also indicate associated aortic stenosis. Differentiating
an aortic flow murmur from concurrent aortic stenosis is difficult. However, if you feel the
carotid, in pure AR it will be really jumping. On the other hand, if there is severe co-existent
AS, the pulse is slowly rise and then rapidly falls away.
The diastolic murmur of AR is heard here. It is important to confirm the murmur occurs in
diastole rather than systole. This can best be done by feeling the radial pulse when auscultating.
SLIDE 14
A TTE is usually the best tool to diagnosis and assess the severity of AR. a TOE less helpful in
AV disease than in MV disease. Key indicators include LV chamber dimensions and systolic
function, AV leaflet morphology and aortic root diameter. We carefully check to see if there is
a tricuspid or bicuspid AV. The aortic root diameter helps to define possible non-rheumatic AV
disease. AR with aortic root dilation may be secondary to certain connective tissue diseases or
even hypertension.
The severity of AR is determined using the length and area of the regurgitant jet as
demonstrated by colour Doppler. LV chamber size and particularly left ventricular end systolic
diameter (LVESD) are also guides to severity.
In moderate to severe AR, there may be reversed diastolic flow in the descending thoracic
aorta. In other words, there is backward blood flow in the aorta during diastole.
Cardiac catheterization and coronary angiography are is only required if symptoms suggest coexistent coronary artery disease or if there is a particularly high risk of coronary artery disease.
SLIDE 15
On the left there is a transthoracic parasternal long axis view. It shows a two dimensional aspect
of the LV on the left. On the right we see the lower MV and upper AV. You can see the LV is
contracting symmetrically.
On the right we can see how the LV chamber dimensions are measured. A line is placed
through the LV, perpendicular to its long axis, usually through the tips of the MV. We measure
the dimension of LV and LVESD in systole. In diastole, we determine the thickness of the
interventricular septum and LV posterior wall. This single dimension view is called the M
mode.
SLIDE 16
We can measure the dimensions of the aortic root and the LA the same way, as seen in the
image on the right.
SLIDE 17
This shows the colour Doppler jet of AR streaming back into the LVduring diastole.
SLIDE 18
And the same jet of AR is shown in real time in this parasternal long axis colour Doppler view.
Note the AR jet just to the left of the AV during diastole.
SLIDE 19
The jet of AR is shown here in a parasternal short axis colour Doppler view. The AV is now
seen in cross-section with the AR jet coming through the centre of the valve. This provides
good views for aortic valve morphology assessment, and is especially useful in excluding nonRHD aortic valve abnormalities.
SLIDE 20
Here is an apical colour Doppler view of AR. In this case the AV is on the left, with the orange
and red jet moving towards the top of the screen.
SLIDE 21
Continuous wave Doppler is used to measure the velocity of blood flow. The image on the left
shows flow of blood across the AV, and on the right, in the descending thoracic aorta.
On the left image, any tracing above the line indicates blood leaking back across the aortic
valve into the LV. The rate of fall of this jet is another measure of AR severity, with more
severe AR taking longer to subside.
The Doppler tracing on the right is of descending thoracic aortic flow. In general, there should
only be minor reversal of blood flow in the aorta at the beginning of diastole. Here there is
reversed flow throughout diastole consistent with severe AR.
SLIDE 22
Having looked at the clinical features AR and the role of echocardiography in diagnosis and
assessment of severity, we can now turn to management of rheumatic AR.
Serial echocardiography is vital for monitoring progression of AR and LV dilatation.
Vasodilators and ACE inhibitors may be tried in moderate to severe symptomatic AR with
preserved LV systolic function. They can limit LV dilatation and the regurgitant fraction.
In the short term, diuretics may also be used to treat symptoms of heart failure whilst awaiting
surgical assessment and intervention.
Atrial fibrillation is uncommon with pure rheumatic AR. It is generally managed with
anticoagulation and rate control medication. Cardioversion to sinus rhythm is a possible option,
but his is controversial. If cardioversion is considered, a period of at least four weeks of
therapeutic anticoagulation and INR monitoring is required.
SLIDE 23
A summary of the key points in AR management can be found in the Australian guidelines.
These can be accessed at the RHD Australia website
SLIDE 24
The Australian guidelines also provide an excellent summary of the key points in the surgical
pathway for AR.
SLIDE 25
It’s time to turn our attention to rheumatic AS. Isolated rheumatic AS is rare. When does occur,
it’s usually in conjunction with rheumatic AR. On the other hand, non-rheumatic AS is
becoming increasingly common. It’s a disease of aging, especially when there is a bicuspid AV.
Listen to the ejection systolic murmur of AS here.
We will now look at the symptoms, signs, echocardiographic features of AS.
SLIDE 26
Symptoms of AS include shortness of breath, fatigue, chest pain and syncope. AS tends to
progress slowly. Symptoms usually start to occur once the mean pressure gradient across the
AV exceeds 40 mmHg and the AV area shrinks to less than 1.0 sq cm.
As mentioned, rheumatic AS stenosis is usually accompanied by AR and MV disease. In such a
setting it’s often hard to decide which valve is causing symptoms. So the general rule should be
that any symptoms from any rheumatic valve disease should prompt early surgical assessment.
SLIDE 27
This TTE shows a parasternal long axis view of the MV on the left, and AV on the right. Note
the AV is thickened and immobile. The MV is similarly thickened with restricted motion, a
reminder that rheumatic AS rarely occurs in isolation.
SLIDE 28
This is a continuous wave Doppler of the velocity across the AV. We can derive the mean
pressure gradient across the AV from the tracing of the wave form.
SLIDE 29
And finally to the management of AS.
There is no role for medical therapy in asymptomatic AS. Regular monitoring is the key. We
watch for development of symptoms and repeat echocardiography to assess AV pressure
gradient and LV function.
When symptoms appear or LV function is impaired it’s time for surgical review and likely
intervention.
Surgical options include bioprosthetic or mechanical valve replacement, percutaneous aortic
balloon valvuloplasty and, nowadays, percutaneous AV replacement.
SLIDE 30
The Australian guidelines provide a summary of the key points in the management of AS.
These can be accessed at the RHD Australia website.
SLIDE 31
The Australian guidelines also provide flowchart for surgical referral of patients with AS.
SLIDE 32
Whatever the nature of the RHD, we only get good outcomes when we understand and address
the major barriers to proper care.
When there are systemic barriers, people present late in the disease, diagnosis is delayed,
treatment options are restricted, we see more complications and outcomes are poor.
Primary health care professionals who care for people with RHD, including Indigenous health
workers, nurses and doctors, need ongoing education about the diagnosis, monitoring and
treatment options. Culturally appropriate education also should be given people with RHD,
their families and the wider community. This requires time and resources. Primary health
service must be properly supported in these endeavours.
Populations at the highest risk for RHD live in remote areas and also tend to be highly mobile.
This can frustrate clinic recall systems, service delivery and proper documentation. Follow up is
difficult. So, RHD prevention programs must work closely with remote primary health services
on a day-to-day basis.
Sending people with RHD to specialist centres for cardiologic assessment is expensive. Public
transport is not always available or reliable. Accommodation is often a challenge.
Communication is difficult. People from the bush can be intimated by large city hospitals.
Appointments get missed. The city clinicians get frustrated. This is where programs focussing
on patient travel services and family support can make a big difference.
The other approach is to send the specialist and the echocardiography machine out to the clinics
in the bush. People with RHD are seen on their home turf and remote clinic staff can provide
local knowledge. These visits also provide opportunities for in-service education for clinic staff.
Managing anticoagulation with Warfarin therapy is always a challenge in people with AF
and/or mechanical prosthetic heart valves,. This is much more so in remote communities, for a
whole variety of reasons. Warfarin-related adverse events, either from too much Warfarin or
too little Warfarin, can lead to devastating and sometimes fatal complications. So Warfarin
therapy requires careful risk management with point of care INR testing, close supervision of
dosing, strict adherence to evidence-based management guidelines and good documentation.
The well-known difficulties with anticoagulation provide a strong argument against using
mechanical valve prosthesis in Aboriginal and Torres Strait Islander people who live in remote
settings. This is especially the case for women of child bearing age who are faced with the
additional issue of anticoagulation in pregnancy.
So it’s essential to appreciate a local perspective when choosing the most appropriate
intervention for RHD, whether it be valvuloplasty, valve repair, bioprosthetic valve
replacement or mechanical valve replacement. Each has their advantages and disadvantages.
What is technically best from the perspective of a surgeon in a large city hospital may have
dramatic adverse implications for the patient once back in the community.
SLIDE 33
So let’s review the take home messages.
 Regular echocardiography and specialist review are essential for ongoing management of
rheumatic AV disease.
 We recommend early referral for surgical assessment once there is moderate to severe
AV disease.
 We recommend the RHD Australia guidelines for management of RHD. They are an
invaluable resource.
 Finally, primary health services are the key to high-quality care. They must be supported
in their endeavours to deliver effective secondary antibiotic prophylaxis, to provide
ongoing education and to maintain regular follow-up of people with RHD.
SLIDE 34
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SLIDE 35
And finally, for those of you who would like to test your knowledge regarding the information
presented in this module please go to the brief self-assessment quiz at the link provided on this
website