Activate or Wait – 008

• Widespread ST depression in leads V2-6, I, II, III, aVF
• Reciprocal ST elevation in aVR
• No Q waves
• No ST elevation in V1-2 that would suggest septal infarction

ST elevation in aVR is a reciprocal change to the widespread ST depression of subendocardial ischaemia, usually most prominent in I, II and V4-6. This is the same ECG pattern seen in patients with a positive stress test.

Oxygen supply-demand mismatch causing subendocardial ischaemia can be due to both cardiac and/or non-cardiac causes:

• Severe triple vessel disease
• LMCA or LAD insufficiency
• Hypotension
• Hypoxia
• ROSC post cardiac arrest

Patients will often have a combination of the above – shock due to sepsis or hypovolaemia may unmask underlying coronary artery insufficiency. Examine other leads closely for changes suggestive of concurrent occlusion myocardial infarction (OMI):

• ST elevation in V2-4 suggestive of anterior OMI
• Isolated ST elevation in lead III suggestive of inferior OMI (Aslanger pattern)
• ST depression maximal in V1-3 that suggests posterior OMI

In the absence of these above changes, acute coronary occlusion is rarely the cause of this ECG pattern. These authors would suggest cardiology review on arrival and strong consideration of non-occlusive causes of ST elevation in aVR. Accredited bedside echo may be useful in guiding initial workup.

PMcardio’s AI ECG model identified a STEMI/STEMI equivalent.

The explainability feature offers insights into problematic patterns in the respective leads, providing a clear rationale for the diagnosis.

Key Finding:

Findings:

• Left Main Coronary Artery – Normal
• Left Anterior Descending Coronary Artery – Normal
• Left Circumflex Coronary Artery – Normal
• Right Coronary Artery – Normal
• Aortogram – Evidence of dissection flap and severe aortic regurgitation

Plan:

• CTS referral made urgently
• Patient transferred to CT then to OT

Further reading

• Harhash AA, Huang JJ, Reddy S, Natarajan B, Balakrishnan M, Shetty R, Hutchinson MD, Kern KB. aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion. Am J Med. 2019 May;132(5):622-630.
• Knotts RJ, Wilson JM, Kim E, Huang HD, Birnbaum Y. Diffuse ST depression with ST elevation in aVR: Is this pattern specific for global ischemia due to left main coronary artery disease? J Electrocardiol. 2013 May-Jun;46(3):240-8. 
• Burns E, Buttner R. ST Elevation in aVR. 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
• Smith SW. Dr Smith’s ECG blog.
• Rawshani A. Clinical ECG Interpretation ECG Waves