How reliable is an ekg as a predictive tool for cardiac ischemia?

Not: Does not predict, but shows rhythym, and evolving changes with ischemia, like in a stress test or myocardial, infarction.

Poor: It is neither sensitive nor highly specific. It's only one tool among many that doctors use. It's helpful for confirming a clinical suspicion if the history is suggestive and the ekg is either dramatically abnormal or changed from a previous tracing. Its value is increased when performed during the index symptom under evaluation.