Adult Congenital Heart Disease in the ED. St Emlyn’s

Virchester is recognised as a specialist centre for patients with adult congenital heart disease (ACHD). This is an interesting and occasionally challenging group of patients who may require some modifications in your approach to referral, management and resuscitation. We also know that the success and progress in the management of children with CHD is leading to an increase in the number of survivors and therefore an increase in the number of adult patients attending the ED¹. This blog outlines some of the key questions we should be asking when an ACHD patient attends the ED and links to some open access learning resources for those of you who want to know more. When we started looking at this it became clear that although there is a fair amount of guidance out there about the management of patients in the surgical and out-patient setting there is relatively little published that is aimed at the Emergency Medicine community²,³,⁴.

This blog post is not designed to be a comprehensive review of ACHD, rather it is to raise awareness and to provide links for future reference. It is based on the introductory course on ACHD put together by the North West ACHD network based in Liverpool.

Background

It’s probably worth just refreshing your knowledge of the common causes of congential heart disease, and the common surgical corrections. Click on the links for further information via youtube.

• Atrial Septal Defects
• Ventricular Septal Defects
• Atrio-ventricular defects
• Transposition of the great arteries.
  • Mustard/Senning procedure
  • Arterial Switch procedure
• Tetralogy of Fallot
• Functional single ventricle (variety of causes e.g. hypoplastic left ventricle)

It’s a good idea to spend some time clicking on the links above to refresh your anatomy, embryology and pathology of the underlying conditions. The links will refresh your memory about what happens in childhood, but from an Adult Congenital Heart Disease perspective, and certainly from the perspective of an emergency physician who may need to be treat the patient, I’m most interested in what happens after surgical correction.

So let’s think about what problems we might see in the ED and how we might manage the patients. I think these broadly fall into the following categories.

• Arrythmias
• Chest pain
• Cyanosed patients
• Endocarditis
• Coarctations repair site problems
• Mechanical Valve problems
• The ACHD patient with a non-cardiac emergency

In general your approach should be similar to in all emergencies. You can adopt an ABC approach and then adjust in some circumstances. For most patients your treatment will be the same as for a non-ACHD patient, but there are some exceptions.

In the UK it’s important to remember that your patient will almost certainly be in contact with a named ACHD cardiologist at one of the UK’s centralised specialist centres. These consultants are on call 24/7 and expect to be called about these patients when they present to the ED. This is a really important, and arguably the most important point in this blog. In many cases the best approach will be to manage the patient in conjunction with your local on-site cardiology team, with the additional remote support of the ACHD team. You can always call for help, and you should. Your patient will probably already have the contact details of their ACHD team, but if they don’t or if they are too unwell to tell you, you can still phone your local centre directly.

Recently we engaged with a range of patients and clinicians who deal with ACHD and it was pretty clear that the experience of patients in many EDs is less than ideal. Whilst that feedback was difficult to hear, it is important that we consider ways that we can improve it.

Arrythmias⁵

These are the most common ACHD related problems that you will see in your ED⁶. ACHD patients have a number of risk factors associated with the development of arrythmias, notably in patients who have undergone some form of surgical repair. In general they can be managed as you would for any adult patient but there are some exceptions. Be mindful that patients can deteriorate rapidly, and be very, very wary about sending them home without specialist input. In fact, DON’T send them home without ACHD review (even if just by phone).

For many patients there may be a relative lack of physiological reserve, so not only do we have concerns about deterioration, but where the patient is already cardiovascularly compromised there is significant urgency and electrical cardioversion is the preferred strategy. A number of patients may respond unpredictably to Amiodarone and so seek advice before using it from the ACHD team. You can learn more about arrythmia management in the following video.

ACHD patients are also at risk of ventricular arrythmias, notably VT. These are especially common in patients with Fallot’s tetralogy or post Mustard/Senning procedure. A number of these patients may have implantable cardiac defibrillators in situ. VT/VF is a cause of sudden cardiac death in these patients.

Fontan circulation patients

A Fontan circulation^7,8 is usually the result of a palliative procedure for CHD. With better paediatric care more of these patients are entering adulthood and so what was once rare is now increasingly seen in the ED⁹. In basic terms a Fontan circulation means that blood flows into the lungs through passive venous pressure. Blood then flows to a functionally single ventricle where it is pumped into the systemic circulation. Such patients are therefore very susceptible to changes in intra-thoracic pressure. If you add PEEP or CPAP to these patients then venous return may plummet, and soon after so will the ventricular output! This is especially the case if the patient is volume depleted and/or if positive pressure ventilation is used. The resus approach should be to maintain venous return (vascular tone, volume, pressure) and to treat any compromised patient with a Fontan circulation as an emergency.

Fontan patients are prone to a number of complications, arrythmias, thromboembolism, obstruction, heart failure, hepatic failure and cyanosis. You can learn more about a failing Fontan circulation in the following video.

Mechanical valve problems¹⁰

In general you can treat ACHD patients as you would any other patient with a mechanical valve. You should be suspicious of endocarditis in a septic patient, and be concerned about thrombosis in pregnant patients, those with older (smaller) valves and those who are less than compliant with anticoagulation. The key thing is to consider and then make the diagnosis (typically with ECHO). Treatment is then somewhat bespoke depending on the circumstances of the patient.

Endocarditis¹¹

Endocarditis should be a consideration in any septic ACHD patient, notably those with mechanical valves and/or previous surgery^12,13.

Chest pain and ACS

Interestingly, and with the exception of coarctation and arterial switch patients, ACS is no more common in ACHD patients than in the general population. However, presentations with chest pain are common amongst ACHD patients, something that some authors have suggested may be related to the psychological burden of the disease. In general you can manage them using standard ACS protocols and in Virchester we would do serial hs-Troponin and ECGs. Just be careful with Eisenmenger patients¹⁴ who’s chest pain may originate from their right ventricular hypertrophy, thus symptoms, signs and ECG changes may be more difficult to interpret. Also be aware that patients with coarctation repairs are more likely to develop aortic dissection or aneurysms in adulthood.

(Usually) Cyanosed patients.

A number of ACHD patients will ordinarily be cyanosed as a result of a shunt between the pulmonary and systemic circulations. These patients often scare emergency physicians as the numbers on the monitor might typically represent an immediate need for intubation, yet the patient is sat there talking to you. They have physiologically adapted to a chronic state so our resuscitation goals and parameters need to take this into account.

There are a number of cautions and considerations in this group of patients.

• Find out what the patient’s baseline physiology is and aim for that. If they normally have O2 sats in the range 78-82 then there is no point, and indeed potentially great danger, in trying to exceed this.
• Cyanosed patients are typically physiologically adapted through a rise in the haematocrit. An Hb of 200 is not unexpected, but again check what’s normal for your patient when they are well and aim for that.
• These factors increase the risk of stroke, paradoxical emboli and arrythmias.
• In patients with a really high haematocrit speak to the lab about samples. You may need special samples/tubes for certain tests such as coagulation studies. If the haematocrit is >0.57 then you will need to use a corrected citrate sample (ask the lab if in doubt).
• Our ACHD team don’t use vacuum systems for taking blood in ACHD patients with high haematocrits. They get too much haemolysed results coming back (and therefore need repeating).

Heart failure¹⁵

Many non surgically corrected ACHD patients have fairly finely balanced haemodynamics and are therefore at risk of heart failure, which is often right sided heart failure¹⁶. They are therefore sensitive to RV pre-load which we can affect through the use of diuretics and vasodilators. It may be the case that the patient with right sided heart failure needs volume support and maintaince of venous tone in contrast to the typical approach for the non-ACHD patient with left sided heart failure that will be familiar to most emergency physicians.

As with all heart failure patients it’s important to seek a reason why your patient has gone into failure. Is it a new arrythmia (common), infection, ischaemia or some other reason for altered haemodynamics.

The ACHD patient with a non-cardiac emergency

Patients with ACHD may present with other medial problems and to some degree this is the group where we have the potential to make errors. If an ACHD patient presents with a cardiac problem then it’s obvious that we would involve expert cardiology, but would we routinely get the ACHD team involved if a patient turned up with appendicitis or a fractured pelvis? Perhaps not, but the recommendation is that we should and I would agree. Patients with ACHD may be at risk of a range of associated morbidities relating to thrombosis, infection, anaesthetic complications and pharmacological management. If in doubt get in contact with the patient’s ACHD team.

Other stuff you should know.

• Always use an IV filter in any patient with a bi-directional or right to left shunt. Failure to do so can lead to stroke, cerebral abscess, sepsis and whole bunch of other dangers. If in doubt about whether it’s needed err on the side of caution and use a filter for your ACHD patient.
• If your patient has a Blalock–Thomas–Taussig shunt (from subclavian to the pulmonary circulation) then take the blood pressure in the other arm.
• If your patient has had a coarctation repair then take the blood pressure in the right arm.

Final thoughts.

This is a challenging area for the emergency physician. ACHD patients are rare, complex and also really quite variable. Whilst a generic approach based on sound resuscitation principles is safe in most cases, there are some important exceptions based on the patients individual physiology, pathology and past surgical or medical history.

Whilst there may be occasions when you have to just do the best that you can using common sense and a good working knowledge of standard resuscitation protocols, in the majority of cases there is no shame, and I would argue an imperative, to listen to the patient and to contact their ACHD team at one of the UK’s specialist centres for advice on management.

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My thanks to Petra Jenkins, Cara Hendry and the ACHD team in Liverpool for providing the links and information in this blog. You can read more about the service here.¹⁷

References and further reading