Long QT Syndrome (LQTS).
The Condition.
Long QT Syndrome (LQTS) is an inherited condition that disrupts electrical activity in the heart, and can cause abnormal heart rhythms, known as arrhythmias. The name ‘Long QT’ refers to the length of the QT interval (part of the heartbeat cycle) when the heart’s electrical activity is measured by an electrocardiogram. LQTS is a rare disorder and can be difficult to diagnose, as the QT interval-length changes are often subtle and somewhat variable – in addition, some medications can lengthen a patient’s QT interval, without any inherited condition being present.
Common Symptoms.
Abnormal heart rhythms caused by LQTS can happen as a result of sudden noises, stress, intense exercise or a slowed heart rate during sleep. Common symptoms of LQTS include:
Palpitations
Blackouts
There is a greater risk of sudden cardiac death among patients who suffer from blackouts, have sodium channel mutations, have previously had a cardiac arrest or have a very long QT interval on their ECG.
Unfortunately, in some cases the first sign or symptom of a heart condition can be a sudden cardiac arrest. If somebody becomes unconscious and is not breathing, call 999, start CPR immediately and ask someone to go and get a defibrillator.
Common Testing.
The main test used to diagnose LQTS is an electrocardiogram, though an exercise test is also often used; an exercise test will sometimes highlight LQTS where the ECG fails to pick it up, because the patient’s QT interval can lengthen during recovery from exercise, indicating that the Syndrome is present. Another method is sometimes performed, called a ‘provocative test’, in which a medicine is given and the QT interval is carefully monitored; this can lengthen the interval and help give a clear diagnosis. Genetic testing can be used, but is still in its infancy for this condition, so clinical diagnosis is much more likely.
How is it treated.
In many cases, LQTS can be treated with medication. If the abnormal heart rhythms experienced are severe, a pacemaker or ICD may be fitted. Patients with ‘potassium channel LQTS’ can be prescribed potassium supplements to control the condition.
Cardiac Risk in the Young (CRY).
Jay’s AIM supports the work of Cardiac Risk in the Young (CRY). CRY holds cardiac screening sessions in locations all over the UK; these sessions are unique for offering an electrocardiogram (ECG) and an echocardiogram, when needed, on the same day. The sessions are free to attend for anyone between the ages of 14 and 35. Crucially, any abnormalities highlighted at a screening session must be followed up with thorough assessment and screening at an Inherited Cardiac Condition (ICC) Clinic.