Parameters:
(1) QRS/T wave angle
(2) changes of acute myocardial infarction (AMI)
(3) QRS nondipolar voltage
(4) heart rate variability
(5) QT interval
(6) history of cardiovascular disease
|
Parameter
|
Finding
|
Points
|
|
QRS/T wave angle
|
0 to 96 degrees
|
0
|
|
|
wide (>= 97 degrees)
|
1
|
|
ECG changes of AMI
|
absent
|
0
|
|
|
present
|
1
|
|
QRS nondipolar voltage
|
< 65 microvolts
|
0
|
|
|
increased (>= 65 microvolts)
|
1
|
|
heart rate variability
|
>= 8 milliseconds
|
0
|
|
|
< 8 milliseconds (low)
|
1
|
|
QT interval and history of cardiovascular disease
|
QT interval < 437 milliseconds OR history of cardiovascular disease
|
0
|
|
|
QT interval prolonged (>= 437 milliseconds) AND no history of cardiovascular disease
|
1
|
where:
• The odds ratios for the risk factors are in the 1.8 to 2.1 range.
• The risk appears to be from all cause cardiovascular mortality (not just coronary heart disease).
• ECG changes of AMI may range from small to massive infarct, which would affect mortality.
total number of risk factors =
= SUM(points for all 5 risk factors)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors: in theory 5, in practice probably 4
• The risk of cardiovascular mortality increases as the number of risk factors increase.
