Screening to prevent sudden death

Each year, infants, children, adolescents, and young adults die suddenly and unexpectedly.  For some a post mortem will identify the cause. In other cases a cause of death will not be found.  The SADS-related genetic heart diseases of long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), Brugada syndrome (BrS), and short QT syndrome (SQTS) are the likely cause of death in many of these cases. These heart conditions have caused the heart rhythm to go into an abnormal and chaotic rhythm (cardiac arrhythmia) from which they could not return naturally. These conditions also known as cardiac channelopathies are treatable.

The Warning Signs and possible genetic implications

Can we screen for these channelopathies and thereby prevent tragic occurrences of sudden death?  The answer is "yes."  In fact, we are screening for these diseases and indeed sudden deaths have been prevented. SADS UK recognize that perhaps 50% of the sudden death victims had preceding "warning signs."  Proper recognition of such warning signs could reduce the number of sudden deaths significantly.  Accordingly, SADS UK strongly advocates for programs that would probe for the presence of such "warning signs" as exercise - or auditory - triggered fainting/seizures and family history of premature sudden death < 40 years of age or unexplained accidents/drownings.  SADS UK is also actively involved in educating family doctors that such conditions can exist in young people and children, by increasing the awareness of the cardiac channelopathies.

Defibrillators to restart the heart

For the other 50% where the sudden cardiac arrest was truly the individual's and their family's first event - rapid access to automatic external defibrillators (AEDs).  SADS UK is involved with school-based and community-based CPR and AED programs.  Whether at the school or on the sportsfield, lives are being saved by effective bystander response with the aid of a defibrillator.

ECG Screening

In terms of ECG screening, this is a very complex issue.  SADS UK believes wholeheartedly in targeted screening. That is screening all members of a family where there has been a young sudden death, or if someone in the family is identified with a condition that could be SADS related. SADS UK strongly believes that highly treatable conditions like LQTS deserves screening to be able to diagnose and treat it before an event occurs.  However, not every patient would present with a diagnostic ECG and currently, there are serious technical and logistical challenges that preclude the use of ECG as a tool for universal ECG screening.  Because of this, SADS UK supports research funding to enable the appropriate scientific studies that are necessary to determine most effective and efficient methods of identifying LQTS.  Our patients and families deserve such a concerted effort.

National Screening Programs

The UK National Screening Committee advises Ministers, the devolved national Assemblies and Scottish Parliament on all aspects of screening policy. The NSC evaluates proposed new screening programmes against a set of internationally recognised criteria covering the condition, the test, the treatment options and effectiveness and acceptability of the screening programme. Assessing programmes in this way is intended to ensure that they do more good than harm at a reasonable cost.

National Screening Committee – response from Chief Medical Officer

I am writing to inform you that the UK National Screening Committee (NSC) has reviewed its policy advice on population screening for Hypertrophic Cardiomyopathy, which is one of the main causes of sudden cardiac death in the UK. They have advised that screening should not be offered. Letter from the Chief Medical Officer, Dr Michael McBride, 2009

See more here - http://www.dhsspsni.gov.uk/hss-md-2-2009.pdf

Response to SADS UK's request for an update on screening for conditions that cause SADS was received on the 24th May 2007:-

The National Screening Committee (NSC) looks at screening programmes individually on a condition by condition basis so at this time we are unable to say what other conditions will be considered during the year or at the same time as hypertrophic cardiomyopathy.

As you are aware, there is insufficient evidence to introduce a screening programme for hypertrophic cardiomyopathy either for the whole population or for specific subgroups but that it will be reviewed during 2007/08.  Unfortunately there is no timescale for this at the moment.  Currently we are awaiting the appointment of a new UK NSC Programme Director and it will be at this time when such decisions are made.

The issues you have raised about GPs assisting with a family history evaluation is one that Mike Yates, who I know you know well, is considering at the moment.  Mike and his colleagues, patient organisations like SADS UK, and 'champions' in the NHS do encourage GPs to do this where they can - the tricky thing is to bring some consistency and quality to this.

As you will appreciate there are lots of things to consider here, but Mike is pursuing this with his colleagues in the Department of Health.  I am sure Mike will keep you informed of progress.

Medical papers covering screening for cardiac conditions

The PDF linked below contains references to a few papers covering the subject of screening, most papers on this subject refer to sports persons engaged in regular competitive sport. We have put them in categories depending on our interpretation of the authors position regarding the value and effectiveness of screening. Please let of know of other studies you find.

Related papers on the pros and cons of screening