Check your pulse.

For one of every four victims, sudden death is the first symptom of cardiovascular problems. Could a simple test help identify seemingly healthy but high-risk individuals before tragedy strikes?

Scientists say the answer may be at our fingertips or on our electronic heart rate monitors.

In an intriguing study of French civil servants, all men aged 42 to 53 whose hearts beat too fast at rest and too slowly while exercising on stationary bicycles were more likely to die suddenly from a heart attack or a fatal rhythm disorder than those with normal pulse rate patterns.

Heart rhythm experts say the apparent cause of the abnormal heart patterns is a problem in the parasympathetic nervous system, which is designed to slow the heart rate after danger or stress.

For the trial, researchers recorded the pulse rate of 5,713 men at rest and while exercising. During the follow-up period, 83 men died suddenly, on average within 11 1/2 years. An analysis of the records showed that the victims had a resting heart rate of more than 75 beats per minute. During stress testing, their heart rate increased by fewer than 89 beats per minute; after exercise stopped, their heart rate dropped less than 25 beats in one minute.

The new findings could help target patients who might benefit most from implanted defibrillators and heart-protective measures such as aspirin therapy, cholesterol-lowering statins, reducing blood pressure, and losing weight. In addition, the research team suggests that cardiologists analyze stress test results for the abnormal pulse patterns as well as for signs of blocked arteries to better determine heart risk.

Checking pulse rate is easy, using fingertips or a stethoscope. To obtain your resting heart rate, find a pulse point at the wrist, neck, or chest. Then count the beats for 10 seconds and multiply by six. Many treadmills and pedometers are now equipped with built-in monitors or chest straps to measure pulse rate during and after exercise.