Getting regular exercise is the best way to prevent most types of heart disease—including sudden cardiac arrest.
New findings may help allay fears about sports-related heart death.
You’ve probably heard at least one account of a middle-aged man who suddenly collapsed and died while exercising. One famous example is James F. Fixx, author of The Complete Book of Running, who in 1984 died of a heart attack at age 52 while jogging.
These anecdotes might give you pause as you lace up your workout shoes. But a new study offers reassurance that exercise-related heart deaths are quite rare, accounting for just 5% of sudden cardiac arrest cases.
“These deaths grab our attention because they’re rare and counterintuitive. But there’s absolutely no question that regular, moderate-intensity exercise is the best way to prevent sudden cardiac arrest,” says Dr. Aaron L. Baggish, associate director of the Cardiovascular Performance Program at Harvard-affiliated Massachusetts General Hospital. The paradox is that if you are going to have a heart-related event, it’s more likely to occur when you’re exercising than when you’re not, he explains.
What can cause sudden cardiac arrest?
Sudden cardiac arrest means the heart abruptly and unexpectedly stops working. It can occur in a person with or without known heart disease. Possible causes include a structural or electrical problem with the heart; dehydration; a serious imbalance of potassium, magnesium, or other minerals in the blood; an inherited condition; or a blow to the chest.
Cardiac arrest is not the same as a heart attack, which is caused by an artery blockage that stops blood flow to the heart. A heart attack can kill part of the heart’s muscle but isn’t necessarily fatal.
However, a heart attack can trigger a malfunction in the heart’s electrical system, which can lead to sudden cardiac arrest. In most of these cases, the heart’s lower chambers beat fast and chaotically, a condition known as ventricular fibrillation. Circulation stops, and death occurs in minutes.
For the study published in the April 21, 2015, issue of Circulation, researchers reviewed 1,247 cases of sudden cardiac arrest in middle-aged men and women over an 11-year period. Of the 63 cases of cardiac arrest that occurred during exercise, most occurred in men, most of whom were jogging, playing basketball, or cycling.
Watch for early warning signs
Two-thirds of these people had known heart disease. In fact, nearly one-third of them had experienced typical cardiovascular symptoms such as chest pain and breathlessness during the week before the sudden cardiac arrest. But the exercisers were twice as likely to survive than people with cardiac arrest from all other causes, probably because they were in public places and more likely to receive quick treatment from a bystander.
In addition to the reassurance that exercise-related cardiac arrest is rare, the study’s other important message is that heart disease often gives warning signs, says Dr. Baggish. If you feel any chest pain during exercise, have difficulty breathing, or even feel more drained than usual, stop and call a doctor for advice.
Recognizing and reacting to cardiac arrest
Someone having a cardiac arrest
If you witness someone collapse from what appears to be cardiac arrest: