ECG of the Week - 27th November 2017 - Interpretation

The following ECG is from a 36 yr old male who presented following an out-of-hospital cardiac arrest. Return of spontaneous circulation was achieved pre-hospital. On arrival the patient has a GCS of 3 (E=1,M=1,V=1).

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Rate:

• Mean ventricular rate ~60 bpm
• Atrial rate ~120 bpm

Rhythm:

• Irregular ventricular complexes
• Regular atrial activity
• AV dissociation

Axis:

• Normal

Intervals:

• QRS - Normal (100ms)

Additional:

• ST Elevation leads II (5mm), III (6mm), aVF (5.5mm)
• ST Depression leads I, aVR, aVL, V1-5

Interpretation:

• Inferior STEMI
• Complete AV block
• Potential RV involvement - STE III>II, high lateral ST depression
• Potential posterior involvement

What happened ?

The clinical scenario surrounding the patient's collapse and the significant decreased conscious level raised the concern of a possible CNS cause of the collapse. The patient was taken for an urgent CT head, which was normal, and then taken for urgent angiography. This showed an occluded RCA, which was stented.

ST Elevation in acute Intra-cerebral events.

Numerous case reports of ST-elevation in the setting of acute sub-arachnoid haemorrhage (SAH). Unfortunately there are no decision rules to help establish an intra-cerebral event vs acute myocardial infarction, suspicion must be based on the individual clinical scenario.
Case reports of ST elevation in acute sub-arachnoid haemorrhage have included changes in all ECG vascular regions. They can also have associated ST depression, an abnormal bedside echo and there is no consistent association with QT prolongation

References / Further Reading

Life in the Fast Lane

• Inferior STEMI
• Raised ICP

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.