Long QT Syndrome and Sudden Cardiac Deaths

So, a slight deviation from the norm, but I figured I write something on this topic following on from my recent physiotherapy in-service training I did on cardiology.

So, Long QT Syndrome became well known in the press in 2012 when Fabrice Muamba of Bolton Wanderer's collapsed on pitch during a FA Cup football match against Tottenham Hotspur.

It's one of the main reasons now that all sporting clubs should have defibrillators as standard, and why there are more being used in public places such as shopping centres.

Long QT is a disorder that is associated with the umbrella term of "Sudden Cardiac Death", which is described as "non-traumatic, unexpected event that occurs due to sudden cardiac arrest".  In order to be clinically considered SCD, the event must occur within 6 hours of previously witnessed typical health (Pugh, Bourke, & Kundian, 2011), and also includes such conditions as Wolf-Parkinson-White Syndrome and Myocarditis.

The "QT" in "Long QT Syndrome" is related to the electrical impulses transmitted within the heart. The QT interval on an ECG is the time taken for the ventricles to repolarize (return to their normal electrical status in preparation for the next impulse/heart beat). This timing should be approx 1/3 of each heart beat cycle for the QT interval, and when this is longer than it should be, it could trigger abnormal heart rhythms called arrhythmias, which can lead to sudden cardiac arrest/death.

 

Long QT Syndrome is a congenital condition, and the first symptoms clinically could be that of sudden cardiac arrest, however, some may experience sudden faints, seizures or arrhythmias. 

It affects roughly 1 in 2000 people, and causes roughly 1-2 deaths per 100,000 athletes per year.

Those who are thought to have Long QT can be diagnosed via ECG, genetic testing or stress test.

Long QT is thought to be caused by lack of ions or ion channels, such as sodium, calcium or potassium ions in the heart that when move across the heart cell boundaries, they stimulate the electrical impulses within the heart.

If Long QT Syndrome is confirmed,  certain lifestyle changes should be incorporated to avoid strenuous activity, such as removal from competitive sport, and some are advised to purchase an external defibrillator as part of their standard kit, or smaller changes such as adding more potassium-rich foods to dietary intake (such as bananas). 

Treatment may also consist of beta blocker medication to slow down the heart rate, to reduce the risk of Long QT causing sudden cardiac death.

Surgery may be required, either to fit a Implantable Cardiac Defibrillator (ICD - see below) or to regulate the nerves of the heart to maintain a normal rhythm.

ICD 

An implantable cardiac defibrillator is much like a pacemaker, and can actually do the same job, providing regular electrical impulses (NOT shocks) to ensure the heart stays in the correct rhythm. The additional bonus of an ICD is that, when required, if an abnormal heart rhythm is detected and is unable to correct with pacing, can provide an electrical shock to the heart to restore normal rhythm.

They sit just under the collarbone on the left and are around the size of a matchbox. They have electrical wires that feed down the blood vessels into the heart. 



Post ICD Insertion

Normal post-surgical precautions
No contact sports incase of dislodging wires or implant
Take care around other devices/objects that omit electrical pulses which may confuse the device

Living with Long QT Syndrome

If Long QT is confirmed, it may be worth taking precautionary steps, such as having a plan in place if sudden fainting or cardiac incident occurs, which involves letting colleagues, friends, family know about your condition.

However, Long QT doesn't mean all has to change, athletes such as Dana Vollmer, an American swimmer who won a gold medal at 2012 Olympics. She was diagnosed with Long QT at 15 years old, but still continued to compete with a debrilliator on the sidelines, and has still had a successful career.

Read more here

If anyone has any experiences of this condition, I'd love to hear about it, via email (thomasbond.physio@gmail.com), Twitter (@Tombondphysio) or just comment below!

References

O'Connor A 2012 Overcoming a heart condition to win Olympic gold. New York Times Blog

Pugh, Andrew, John P. Bourke, and Vijay Kunadian. Sudden cardiac death among competitive adult athletes: a review. Postgraduate medical journal 88.1041 (2012): 382-390.

National Heart, Lung and Blood Institute 2011 What is Long QT Syndrome?

Heart and Stroke Foundation 2011 What is Long QT Syndrome?

Khan 2014 Introduction to Long QT Syndrome: A Cause of Sudden Cardiac Death in Athletes. BMJ Group

 British Heart Foundation Implantable Cardiac Defibrillator Patient Leaflet