You may notice automatic defibrillators hanging on the wall in a bank, a school, a big store. Atrial fibrillation is disconcerting, surely. It’s rapid fluttering of atria, floppy chambers in the heart that feed the strong pumps, the ventricles. Overall heart output is down and one feels weak or giddy. In the long term one has a greater risk of blood clots.
A defibrillator shoots an electric shock through the chest to stop a nasty episode of Afib. There are many possible causes of Afib – age, heart disease, genetics, irregularities in nerves on the heart… or no known cause (I had Afib at times when I was younger.) Here’s another strange cause: training for extreme athletic events – elite rowing competitions, marathon running, the Tour de France.
Exercise cardiologist Andre La Gerche in Melbourne, Australia and others study these super-athletes. Elite rowers in one study had an Afib rate of 20%, compared to 3% in the general population. In a Danish study 40% of people with Afib developed heart failure and 20% had a stroke. Why? A major lead being followed is that extreme exercise leads to enlarged hearts – powerful, but so large as to push against the chest or spine, becoming inflamed. More leads are being followed. What’s to be done? Blood thinners reduce the risk of stroke; reduced training is the best bet, even at the cost of giving up some athletic performance.
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org
Source: Science, 17 May 2024, pp. 722-3.
