### Description

The Cardiac Infarction Injury Score (CIIS) was developed to identify ischemic heart disease based on changes in the electrocardiogram. It may also have prognostic significance in predicting coronary heart disease mortality.

Item

Parameter

Finding

Contribution

1

duration of Q in aVL

Q absent

5

10 ms

1

20 ms

3

30 ms

9

40 ms

10

50 ms

12

2a

amplitude of positive T in lead aVL

<= 0.5 mm

3

> 3 mm

3

2b

amplitude of negative T in lead aVL in mm

if negative, else 0

2 * (number of mm)

3

amplitude of negative QRS in lead aVR < 5 mm

(-1) * (number of mm)

4

amplitude of negative T in lead aVR

no negative phase (positive or 0)

6

1 mm

3

2 mm

-5

3 mm

-8

4 mm

-10

5 mm

-12

6 mm

-14

7 mm

-16

8 mm

-18

5

largest Q/R amplitude ratio on lead II or aVF

>= 0.2 (1/5)

12

6

duration of Q in lead III or aVL

>= 40 ms

5

7

amplitude of T in lead III

> 1 mm

7

8

amplitude of positive T in lead V1

> 2 mm

4

9

amplitude of R in lead V2

< 3 mm

5

>= 14 mm

5

10

amplitude of negative T in lead V2

>= 0.25 mm

5

11

largest Q/R amplitude ratio in lead V3

> 0.05

9

12

amplitude of S in lead V5

< 2 mm

5

where

• amplitudes 1 mm = 0.1 mV

• absolute values for negative amplitudes used

• for item 1, Q duration measured to nearest threshold

• in item 2, I have taken that 2a is applied if T is >= 0, and 2b if T is negative

• T amplitude is measured as the absolute value of the largest deflection above and below the PR baseline in a window spanning from 80 msec after the end of the QRS to the end of T

• questions 5 to 12 are answered "yes" or "no"

• in item 10, it is implemented on the following reading: The T wave is negative and ABS(T in mm) >=0.25, which works out to T wave as a negative value is <= -0.25 mm.

• definitions of codable waves are on page 256 of Rautanharju (1981)

NOTE:

• Table is that in Dekker (1994, Table 1 page 40) which is described as being revised in consultation with Dr Rautanharju.

• Table Rautaharju (1981, Table 3 page 251) differs in

(a) item 3: amplitude of negative R in lead aVR, with threshold -1, rather than negative QRS

(b) item 4: values for amplitude of negative T wave in aVR for 2 mm to 8 mm are 2 mm = 0, 3 mm = -2, 4 mm = -5, then subtract 2 additional points for each mm exceeding 4 mm (-7, -9, -11, -13)

(c) item 5: ratio was if >= 0.05 (1/20)

• I am confused in Item 3 by the "< 5mm"; it could be taken to mean to include it only if the QRS is negative and < 5 mm (-1 to -4), or the something else. I implemented the negative amplitude in mm since this matched that in Rautaharju (1981)

cardiac infarction injury score =

= SUM(contribution points)

Interpretation

In patients being evaluated for myocardial infarction, a CIIS >= 20 indicates probable myocardial infarction.

CIIS

Diagnosis of myocardial infarction

20

probable injury

15

possible injury

10

borderline abnormality

The CIIS is a risk indicator for coronary heart disease mortality in the general population.

CIIS

Risk for coronary artery disease mortality in general population

<= 0

low

1 - 10

intermediate

> 10

high