The QRS scoring system involves the evaluation of the electrocardiogram after an acute myocardial infarction and can be used to assess infarct size and left ventricular function. This is the initial "simplified" scoring system, with a subsequent "complete" system described in the next section.
Patient exclusion criteria:
(1) left ventricular hypertrophy or
(2) conduction defects
|
Lead |
Duration in ms |
Amplitude Ratio |
Points |
|---|---|---|---|
|
I |
Q wave >= 30 ms |
|
1 |
|
|
|
R/Q <= 1 |
1 |
|
II |
Q wave >= 40 ms Q wave >= 30 ms |
|
2 1 |
|
aVL |
Q wave >= 30 ms |
|
1 |
|
|
|
R/Q <= 1 |
1 |
|
aVF |
Q wave >= 50 ms Q wave >= 40 ms Q wave >= 30 ms |
|
3 2 1 |
|
|
|
R/Q <= 1 R/Q <= 2 |
2 1 |
|
V1 |
any Q wave R >= 50 ms R >= 40 ms |
|
1 2 1 |
|
|
|
R/S>= 1 |
1 |
|
V2 |
[any Q wave or R wave <= 20 ms] R >= 60 ms R >= 50 ms |
|
1
2 1 |
|
|
|
R/S >= 1.5 |
1 |
|
V3 |
[any Q wave, or R wave <= 30 ms] |
|
1 |
|
V4 |
Q wave >= 20 ms |
|
1 |
|
|
|
R/Q or R/S <= 0.5 R/Q or R/S <=1 |
2 1 |
|
V5 |
Q wave >= 30 ms |
|
1 |
|
|
|
R/Q or R/S <= 1 R/Q or R/S <=2 |
2 1 |
|
V6 |
Q wave >= 30 ms |
|
1 |
|
|
|
R/Q or R/S <= 1 R/Q or R/S <=3 |
2 1 |
|
Leads |
Maximum Points |
|---|---|
|
I |
2 |
|
II |
2 |
|
aVL |
2 |
|
aVF |
5 |
|
V1 |
4 |
|
V2 |
4 |
|
V3 |
1 |
|
V4 |
3 |
|
V5 |
3 |
|
V6 |
3 |
|
total |
29 points |
Table based on data in Table 1, Palmeri et al (1982).
(1) In Seino et al (1983), V4 is graded with a R/Q or R/S <= 1.5.
(2) In Roubin et al (1983) the values are listed as "> or <" rather than ">= or <=".
Interpretation:
• minimum score: 0
• maximum score: 29
• 27 of 30 patients with QRS score > 3 had left ventricular ejection fractions < 50%
• 23 of 25 patients with QRS scores <=3 had normal global left ventricular function
• Patients with QRS scores < 6 showed better exercise tolerance than those with scores > 6 (all with scores < 6 had an exercise tolerance > 5 minutes; about half of the patients with scores > 6 could not exercise more than 5 minutes).
• The QRS score is related to survival, with higher QRS scores associated with a lower survival rate. From Figure 2 of Boundous (1988), the 5 year survival rate for QRS scores of 0 is 88%, 1-3 is 80%, 4-6 is 66%, 7-9 is 64%, and >= 10 is 52%.
Infarct Size and Left Ventricular Ejection Fraction
QRS scores 1 week after onset correlate with infarct size and left ventricular ejection fraction.
infarct size in CK•g•Eq =
= (5.24 * (QRS score at 1 week)) + 8.50
left ventricular ejection fraction at 1 week =
= 59.58 - (2.16 * (QRS score at 1 week))
left ventricular ejection fraction at 3 weeks =
= 59.6 - (3.03 * (QRS score))
left ventricular ejection fraction at 8 weeks =
= 60.2 - (2.9 * (QRS score))
general equation for left ventricular ejection fraction =
= 60 - (3 * (QRS score))
Specialty: Cardiology
ICD-10: ,
