Adverse CV events associated with excessive exercise

EXCESSIVE endurance training over a long period may cause structural and electrical cardiac remodelling leading to arrhythmias and increased CV risk, researchers have suggested.

A review concludes chronic training and competing in extreme endurance events such as marathons, triathlons and very long distance cycling may be too much of a good thing.

“Long-term excessive endurance training may cause adverse structural and electrical cardiac remodelling, including fibrosis and stiffening of the atria, right ventricle, and large arteries. This theoretically might provide a substrate for atrial and ventricular arrhythmias and increase cardiovascular risk,” the authors said.

Associate Professor David Prior, a specialist in sports cardiology at St Vincent’s Hospital, whose work on right ventricular dysfunction after endurance exercise was included in the review, said a national screening program might cost up to $3 million per death prevented.

Alternatively, sports clubs in Australia could be equipped with defibrillators and trained in CPR in a drive to reduce deaths, he said.

“This might be more cost effective than screening a lot of people with false positives. A big piece of data that is missing is how often this happens in Australia.

“We don’t want to give people the message to do less exercise. We need to know why this is happening to some people and not others,” Professor Prior said.
Mayo Clin Proc 2012; 87:587-95