Patient selection: asymptomatic adult males from 42 to 53 years of age
Followup: 23 years
Outcome: sudden death
Exercise protocol: bicycle exercise with 2 minutes at 82 W, 6 minutes at 164 W, and 2 minutes at 191 W (total time 10 minutes)
Parameters (defined in the Exercise Test Protocol, page 1952):
(1) resting heart rate in beats per minute
(2) heart rate increase during exercise in beats per minute
(3) heart rate decrease at 1 minute after stopping exercise
heart rate increase during exercise =
= (maximum heart rate during exercise) - (resting heart rate)
heart rate decrease at 1 minute =
= (maximum heart rate during exercise) - (heart rate 1 minute later)
|
Parameter
|
Finding
|
Points
|
|
resting heart rate
|
<= 75 beats/minute
|
0
|
|
|
> 75 beats/minute
|
1
|
|
heart rate increase during exercise
|
>= 89 beats/minute
|
0
|
|
|
< 89 beats/minute
|
1
|
|
decrease in heart rate at 1 minute after stopping
|
>= 25 beats/minute
|
0
|
|
|
< 25 beats/minute
|
1
|
where:
• The relative risk for the 3 factors on multivariate analysis range from 2.1 to 4.0.
total number of risk factors =
= SUM(points for all 3 parameters)
Interpretation:
• minimum score: 0
• maximum score: 3
• The higher the number of risk factors the greater the risk of sudden death.
