Terminal QRS Distortion

Terminal QRS distortion is an abnormal ending to the QRS complex (the J point) that indicates ischemia. It is most commonly used for differentiating OMI from early repolarization (or other benign causes of ST elevation). The definition is a lack of both an S wave and J wave in V2 or V3 (LAD territory). Remember, patients should have an S wave in these leads as the QRS is still overlying the right side and will be transitioning to the left side (hence the R wave progression). This is more obvious when the descending limb of the R wave never actually returns to baseline before there is ST elevation. However, a lack of terminal QRS distortion does not always mean a benign etiology of the ST elevation. 

Examples:

Further Reading:

http://hqmeded-ecg.blogspot.com/search/label/terminal%20QRS%20distortion