Heart Beat: Exercise no trigger for defibrillator shocks

A carefully tailored exercise plan can strengthen a failing heart while keeping its owner out of the hospital and living longer. Does this apply to the growing number of people with heart failure who have a defibrillator (ICD) implanted, or does exercise cause these devices to deliver unnecessary shocks as the heart speeds up during exercise?

The HF-ACTION trial compared a structured exercise plan against generic advice to exercise among 2,331 men and women with heart failure. At the end of the two-year trial, fewer people in the exercise group had died of cardiovascular disease or were hospitalized for their heart failure. Among the 1,053 volunteers who had an ICD, 20% in the exercise group had received at least one shock from their device, compared to 22% in the exercise-advice group (American College of Cardiology meeting, March 15, 2010). Shock rates were slightly higher in volunteers with atrial fibrillation, atrial flutter, or ventricular tachycardia.

To continue reading this article, you must login.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »