ST segment elevation: MI or not?

When confronted with electrocardiographic ST elevation it’s necessary to differentiate STEMI from early repolarization, pericarditis and other conditions. Look for reciprocal ST depression, which strongly favors MI. According to a study in the American Journal of Emergency Medicine sensitivity, specificity, positive predictive value, and negative predictive value for the electrocardiographic diagnosis of AMI were 69%, 93%, 93%, and 71%, respectively. This works only in the absence of confounding abnormalities such as bundle branch block, paced rhythm and hypertrophy.