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Long QT Syndrome

What is Long QT syndrome?

Long QT Syndrome is a heart rhythm disorder that can lead to sudden, uncontrollable, and dangerous arrhythmias.

Essentially it causes the heart to take longer to return to its resting state following the electrical signal that triggers each heartbeat. When that happens, it can put the heart at risk of going into life-threatening arrhythmia.

It can be genetic – caused by a gene mutation – or triggered by external factors such as side effects to certain medicines and mineral imbalances.

Long QT is a rare syndrome that is estimated to affect between one in 2000- 7000 people.

What are the symptoms of Long QT?

Many people don’t have any symptoms, and often only find out when they have an electrocardiogram (or ‘ECG’).

For those that do have symptoms they can include:

How do you diagnose Long QT syndrome?

If you experience any of the above symptoms talk to your GP who can refer you to a specialist who can make a formal diagnosis by running a series of tests.

How is Long QT treated?

Treatment will vary depending on whether your Long QT is inherited and caused by a genetic mutation or triggered by a mineral imbalance or reaction to certain medications.

For those with inherited Long QT treatment can include:

Non inherited Long QT

For those with Long QT caused by a reaction to medication, your specialist will work with you to analyse which drug is triggering the reaction. In some cases, simply stopping taking the drug and using a safer alternative may prevent any further Long QT symptoms. Other patients may require extra treatment.

Around 100 drugs have been associated with causing Long QT – many of them common including anti-depressants, antibiotics, and diuretics.

If your Long QT is associated with a mineral imbalance such as being deficient in potassium or magnesium, the first step is to identify and fix the imbalance. Patients may require no extra treatment.

What is the long-term outlook for people with Long QT?

If untreated and symptomatic up to 20 percent of people with Long QT may die within a year. But once diagnosed and treated, the prognosis for people with Long QT is good with the risk of suffering cardiac arrest dropping to less than 1% over 20 years.

Acknowledgement of Country

The Victor Chang Cardiac Research Institute acknowledges Traditional Owners of Country throughout Australia and recognises the continuing connection to lands, waters and communities. We pay our respect to Aboriginal and Torres Strait Islander cultures; and to Elders past and present.

Victor Chang Cardiac Research Institute - The Home of Heart Research for 30 Years