EKG Criteria for Fibrinolysis: What’s Up with the J Point?

intrOdUctiOn Reading EKGs is an integral skill in Emergency Medicine, especially given the fact that determining the presence and amount of ST segment elevation (STE) is one of the key factors to initiating fibrinolytic eligibility. STE is generally measured in reference to the J point (the end of the QRS segment and the beginning of the ST segment). However, it may not be clear in clinical practice where the J point starts, where one measures ST segment elevation in relation to the J point and finally what the exact degree of elevation of the ST segment makes one a candidate for thrombolysis. Further complicating the issue are numerous other causes of J point and ST segment elevation that are not myocardial-infarction related. This short review will focus on identifying the J point in order to determine an accurate measurement of ST segment elevation and its relationship to fibrinolytic eligibility.