Heart Rate Reveals Risk of Sudden Death
Test May Show Heart-Rate Abnormalities in Seemingly Healthy Men
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
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
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
Three findings stood out:
- A heart rate of more than 75 beats per minute before exercise (resting
- An increase of less than 89 beats per minute during peak 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
- 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' Hôpital Euopéen 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
'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
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.