R.E.B.E.L. EM - Posted by Salim Rezaie
Bischof JE et al. ST Depression in Lead aVL Differentiates Inferior ST-Elevation Myocardial Infarction from Pericarditis. AJEM 2015 [Epub Ahead of Print] PMID: 26542793
"Background: As emergency providers we must be smarter than our ECG machines. Many times subtle findings on ECGs are not read by the machine, but we must be the experts at making the distinction between findings that require emergent treatment versus more benign etiologies. One specific set of diagnoses that can be very difficult to distinguish from each other is inferior STEMI vs Pericarditis. ECG experts discuss strategies such as looking at morphology of ST-segments (i.e. concavity or convexity), but this is not always accurate. Another, frustrating fact is that ST-elevation in the inferior leads (II, III, aVF) is typically seen with inferior STEMI and pericarditis. We therefore need a finding that has both a high sensitivity and specificity for MI.
Author Conclusion: “When there is inferior ST-segment elevation, the presence of any ST depression in lead aVL is highly sensitive for coronary occlusion in inferior myocardial infarction and very specific for differentiating inferior myocardial infarction from pericarditis.”
Clinical Take Home Point: In the presence of inferior STE, look at lead aVL next. If there is ST depression in lead aVL, treat the patient for inferior myocardial infarction due to coronary occlusion and not as pericarditis."
http://rebelem.com/inferior-stemi-pericarditis/