There’s the case of a woman who didn’t learn she had genetic LQTS till age 82, yet had never suffered a sudden cardiac arrest.
But that’s a very exceptional case. On the other hand, nobody knows just how many people live into old age with undiagnosed long QT syndrome.
What’s only known is that every so often, the condition is first diagnosed in someone well past middle age. Usually LQTS is diagnosed in childhood or young adulthood.
How do people live as long as the 82-year-old with untreated genetic long QT syndrome, while others suffer from a sudden cardiac arrest at a very early age?
“There are numerous genes that can cause long QT syndrome,” says Paul Rogers, MD, Medical Director, Cardiac Rhythm Device Clinic, Ochsner Health System.
Dr. Rogers continues, “However, the majority are accounted for by three different genes causing long QT syndromes 1, 2 and 3.
“Some people are more affected by the mutation than others, a term in genetics called incomplete penetrance.
“In addition to the genetic mutation there are other factors that may influence whether someone develops symptoms like age, gender, the type of genetic mutation and environmental factors.”
One environmental factor that may play into earlier diagnosis is athletic participation. Physical exertion can cause symptoms depending on the type of LQTS.
“Generally speaking, adults with LQTS who have not had clinical symptoms yet, such as passing-out spells, or have survived sudden cardiac death, have continued but diminishing risk of sudden death from LQTS as they age.”
In summary, there is no data on how long a person can live with undiagnosed — and therefore untreated — long QT syndrome.
The congenital version of this condition is rare, so don’t let health anxiety trick you into thinking that you might have it, especially if you’re older and have never had any serious medical problems.