Endurance and high intensity exercise can bring on ARVC in affected people

15th September 2015

A study in America has been looking at the effect of endurance exercise on people at risk of developing arrhythmogenic right ventricular cardiomyopathy (ARVC).

The study, from the cardiology division at Johns Hopkins University in America, followed how the disease came on in family members with a gene mutation for the disease but no clinical signs of it.

It has long been thought that exercise may bring on the development of the disease in those carrying gene mutations for it.

The researchers wanted to find out if endurance exercise and exercise intensity increased the likelihood of family members getting a diagnosis of ARVC and dangerous heart rhythms, and if restricting exercise to the American Heart Association’s minimum goal for healthy adults improved outcomes for family members.

The researchers looked at 28 family members inheriting a PKP2 desmosomal (regulating cell to cell cohesion) gene mutation from ten people with ARVC.

They were interviewed about exercise from age 10.

After adjustment for age, sex, and family membership, taking part in endurance athletics and higher intensity exercise was associated with a diagnosis of ARVC. Endurance athletes were also significantly more likely to develop dangerous heart rhythms. These were ventricular tachycardia (VT), a type of abnormal heart rhythm that causes your heart to beat too fast (usually over 100 beats per minute) or ventricular fibrillation (VF), the most serious heart rhythm disturbance which causes the lower chambers of the heart to quiver and not pump blood, leading to a cardiac arrest.

Family members who restricted exercise to or below the AHA exercise minimum were significantly less likely to be diagnosed with ARVC and had no dangerous heart rhythms.  At diagnosis and the first episode of a dangerous heart rhythm, family members had accumulated around three times the exercise hours of the AHA-recommended minimum. Those who developed VT and VF had done particularly high intensity exercise in adolescence.

The researchers concluded that the survey results suggest restricting unaffected desmosomal mutation carriers from endurance and high-intensity athletics, but potentially not from AHA-minimum recommended levels of exercise for healthy adults.