This is a case I had about a decade ago.

This is a 51 year old who was playing cards with his friends when he started to have left hand numbness.  They were worried he was having a stroke and so called 911.  The medics had just learned to do ECGs, and so recorded one.  Here it is, at 1915:

Diagnostic of Anterior STEMI.  It cannot be anything else.

I activated the cath lab at 1929 based on this ECG.

Then, I questioned the patient at length and his only symptom was subjective left hand paresthesias.  He had no pain, discomfort, or tightness of any kind, no weakness, and no SOB.  So I had a hard time believing the ECG.  I thought perhaps it was recorded with lead misplacement.

So I did the first ED ECG at 1931:

STE is resolved (but there are de Winter’s T-waves in V2 and V3 (hyperacute T-wave with depressed ST takeoff)         Previously published in:  Harrigan (Ed.). The ECG in Emergency Medicine.   Smith SW and Whitwam W.  The ECG in Acute Coronary Syndromes.    EM Clinics of N Am 24(1):53-89; Feb 2006]

With no more overt STEMI, and (through bad thinking and “Nah, couldn’t be…..”) I thought that there must have been some mistake in recording the first ECG.  At worst, if it was a STEMI, I thought that it is reperfused.  I cancelled the cath lab activation for the team that would have to come in from home.   

(Today I would have unequivocally interpreted leads V2 and V3 as LAD occlusion).

At 1942, the patient started becoming hypotensive, so I recorded another ECG at 1946:

Need I say more?  Obvious anterior STEMI. Previously published in:  Harrigan (Ed.).  The ECG in Emergency Medicine.   Smith SW and Whitwam W. The ECG in Acute Coronary Syndromes.    EM Clinics of N Am 24(1):53-89; Feb 2006

I activated the cath lab again at 1946, so that I had caused a 17 minute delay by cancelling.

He went to the cath lab, had an LAD occlusion, then died just before it could be opened.

I learned 2 major lessons from this:

1. STEMI, even if it spontaneously resolves, is very high risk and must go to the cath lab.

2. A clearly diagnostic ECG is diagnostic even if it does not match the symptoms.

  (One cannot make the same conclusion about ECGs that are only highly suspicious – these are more likely to be false positives in the context of atypical symptoms.)