Activate or Wait – 003

• Concave ST elevation inferiorly in leads II, III and aVF — although pericarditis often presents with diffuse ST elevation, it can be localised to a single territory
• Minimal ST depression in aVL and V2
• PR segment depression in lead II, III, aVF, V3-V6
• Downsloping TP segment in V3-5 (Spodick sign)

Note that this is a difficult case where clinical correlation guides interpretation and decision making. Remember that the diagnosis of STEMI requires both ECG changes AND clinical symptoms consistent with an acute coronary syndrome (ACS).

Features such as concave ST elevation and PR depression are more suggestive of pericarditis, however they can also be seen in acute ischaemia. If this same patient presented with one hour of acute chest pain, it would be most appropriate to activate the cath lab.

Given the time until arrival (30 minutes), these authors would suggest requesting serial ECGs at 10 minute intervals from paramedics and an update if there is a change to the clinical condition, as well as a phone call to the cardiology team with planned review on arrival.

The cath lab was not activated prior to arrival. The patient was reviewed in ED by the cardiology team and taken to emergent angiography due to concern for ECG findings.

Key Finding:

No obstructive coronary artery disease. Likely peri/myocarditis.

Findings:

• Left Main Coronary Artery – normal
• Left Anterior Descending Coronary Artery – Type III vessel. Mild coronary plaque proximal vessel. Mild diffuse disease throughout remainder of vessel
• Left Circumflex Coronary Artery – mild diffuse disease. Moderate marginal disease.
• Right Coronary Artery – large dominant vessel. Mild diffuse disease
• Left Ventriculogram – normal systolic function

Plan:
Non-obstructive coronary artery disease. Likely peri/myocarditis.

1. Serial troponins
2. Transthoracic echocardiogram
3. Ongoing aggressive cardiovascular risk factor management
4. Admit CCU

Further reading

• Buttner R, Burns E. Inferior STEMI. LITFL
• Burn E, Buttner R. Pericarditis. LITFL
• Nickson C. STEMI Management. LITFL

Online resources

• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves
• Smith SW. Dr Smith’s ECG blog.