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Acute Myocardial Infarction (AMI) Normalization Criteria after Angioplasty

Purpose: To determine if reperfusion has occurred after primary angioplasty in a patient with an acute MI using the sum of ST segment elevations.

Description

van't Hof et al gave criteria for the degree of normalization of ST segment elevation following primary angioplasty in a patient with an acute myocardial infarction. This correlates with prognosis for the patients. The authors are from the Zwolle Myocardial Infarction Study  in Zwolle, The Netherlands.


Exclusion: new bundle branch block, ventricular pacemaker, sustained idioventricular rhythm

 

Timing of 12-lead ECG: on admission and 1 hour after primary angioplasty

 

The leads used to determine the ST segment elevation for the patient depended on the location of the infarction (anterior vs non-anterior):

 

Leads Summated for an Anterior AMI

Leads Summated for a Non-Anterior AMI

I

II

aVL

III

V1

aVF

V2

V5

V3

V6

V4

 

V5

 

V6

 

 

total ST segment elevation =

= SUM(elevation in ST segment from baseline)

 

percent decrease in total ST segment elevation =

= 100% * (1 - ((total ST segment after angioplasty) / (total ST segment before)))

 

residual ST segment elevation =

= ((total ST segment after angioplasty) / (total ST segment before))

 

Criteria

ST Segment Elevation

Interpretation

no residual ST segment elevation >= 0.1 mV in any lead

complete resolution

normalized

residual ST segment elevation after therapy < 70% of initial elevation

partial  resolution

improved

residual ST segment elevation after therapy >= 70% of initial elevation

no resolution

unchanged

 

 

ST Segment Elevation

Relative Risk for Death

95% CI

complete resolution

1.0

 

partial resolution

3.6

1.6 to 8.3

no resolution

8.7

3.7 to 20.1

 


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Specialty

Objective

ICD-10