Simple Test May Show Heart-Rate Abnormalities in Seemingly Healthy Men

[MORTARDUDE]

Heart Rate Reveals Risk of Sudden Death

Test May Show Heart-Rate Abnormalities in Seemingly Healthy Men

By Miranda Hitti
WebMD Medical News Reviewed By Brunilda Nazario, MD
on Wednesday, May 11, 2005


May 11, 2005 -- A man's risk of sudden death may show up in a simple exercise test, say French doctors.

Ten minutes or less of pedaling on a stationary bike was all it took, they report in The New England Journal of Medicine.

The danger signs were clear in hindsight. When the test was done, the men were apparently healthy, say Xavier Jouven, MD, and colleagues.

All the more reason not to take your heart for granted. Heart disease (which includes heart attacks) is a leading cause of death for men and women in the U.S.

French Findings

Jouven and colleagues followed more than 5,700 French men for 23 years. The exercise test was given at the study's start, when the men were 42 to 53 years old.

All of the men worked for the French government. Age, diabetes, smoking, cholesterol, and other risk factors were noted.

During the test, the men cycled for up to 10 minutes. Their heart rate was monitored before, during, and after exercise. If their heart rate got dangerously high, the test was stopped early.

Nearly a quarter of a century later, 81 men in the group had died suddenly.

Three findings stood out:

A heart rate of more than 75 beats per minute before exercise (resting heart rate)
An increase of less than 89 beats per minute during exercise
A decrease of less than 25 beats per minute after exercise
The normal range of resting heart rate can vary. The American Heart Association (AHA) says the normal range is 60-80 beats per minute.

Raising the Risk

Each of those heart-rate problems raised the men's risk of sudden death from cardiac arrest. Sudden death occurs when the heart abruptly loses its capacity to pump. The electrical impulses in the heart become rapid or irregular (arrhythmia).

An increased resting heart rate nearly quadrupled the men's risk.
Men with hearts that were sluggish during exercise were 6.2 times more likely to experience sudden death.
Those with hearts that had trouble slowing down after exercise had roughly double the risk of sudden death.
After adjusting for other risks, "these three factors remained strongly associated with risk of sudden death," writes Jouven, who works in the cardiology department of Paris' H?pital Euop?en Georges Pompidou.

The three heart-rate problems were also linked to a "moderate but significant" risk of death from any cause. However, they weren't associated with nonsudden heart attack deaths. (Heart attacks can cause sudden death but don't always).

'Powerful Predictor' of Sudden Death

Heart rate during exercise and recovery is "a powerful predictor of the risk of sudden death" in seemingly healthy men, say researchers.

Such tests could help doctors identify and treat high-risk men, they note.

Smoking, obesity, diabetes, high blood pressure, high cholesterol, physical inactivity, and depression (especially in heart disease patients) have also been shown to be heart hazards.

Many of those risk factors can be improved. For instance, exercise, stress control, and a healthy diet can help; so can medications, when needed. Doctors can assess your risk and outline your options. Seek immediate help if you sense any heart problems.

What to Do

The American Heart Association statement on preventing heart attacks and deaths from coronary disease recommends 30-60 minutes of moderate-intensity activity three to four times a week in addition to lifestyle changes.

Knowing how to take your heart rate (pulse) at resttake your heart rate (pulse) at rest can help.

Calculating your peak (or maximum) heart rate can be done by using the following formula:

220 - Your Age = Predicted Maximum Heart Rate

Example: a 40-year-old's predicted maximum heart rate is 180.

Talk to your doc if these numbers seem high.


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SOURCES: Jouven, X. The New England Journal of Medicine, May 12, 2005; vol 352: pp 1951-1958. American Heart Association: "Heart Attack, Stroke & Cardiac Arrest Warning Signs." American Heart Association: "Aspirin in Heart Attack and Stroke Prevention."