Sgarbossa Criteria ECG

Source:http://clinicalmedicineupdate.blogspot.com/2006/04/ecg-zone-sgarbossas-criteria-not-just.html

The presence of left bundlebranch block on the electrocardiogram may conceal the changes of acute myocardial infarction, which can delay both its recognition and thrombolytic treatment.

Elena.B.Sgarbossa et al tested electrocardiographic criteria for the diagnosis of acute infarction in the presence of left bundle-branch block in patients enrolled in the GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) trial who had left bundle-branch block and acute myocardial infarction confirmed by enzyme studies were blindly compared with the electrocardiograms of control patients who had chronic coronary artery disease and left bundle-branch block. The criteria studied is given in the table below.

They found that ST-segment deviation was the only electrocardiographic finding that was useful in the diagnosis of acute myocardial infarction in the presence of left bundle-branch block. Previously proposed electrocardiographic signs involving the QRS complex were not useful.

 The ST changes that were significant are: 
1.ST elevation > or = 1mm and concordant with QRS.
2.ST depression > or = 1mm in v1,v2 or v3.
3.ST elevation > or = 5mm and discordant with QRS. ---