Cardiac Infarction Injury Score

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.

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