12 lead EKG

Is it possible to have a normal or unchanged EKG and still be having an MI?  An 80 years old male patient had a history of a lateral wall MI d/t vasospasm in the past, and had intemittent "arthritic type" chest pain over the past few month.  His primary worked him up with labs and a stress test in Dec 2010 and everything came back ok.  He presented to his PMD at 4pm yesterday with the same chest pain and left arm numbness/soreness that was new, but the patient also said he had been moving, stressed, and lifting boxes.  When he saw his PMD the chest pain was gone, and was reproduced when his chest was palpated.  His still had a little soreness to his arm.  His 12 lead showed NSR with 1 degree AVB which was unchanged from his previous 12 lead.  No complaints of nausea, vomiting, dizziness, diaphoresis, etc.   Rest of the physical showed up as normal.  The PMD examined him but told him it was 90% not cardiac but he needed to come immediately if the pain came bcame back/got worse, and that he didn't feel he had to draw labs at that time.  Six hours later the patient presented with chest pain that radiated to both shoulders and lasted one hour, was pale, diaphoretic, and had 2-3mm ST elevation in his inferior leads.  Was anything missed at the PMD?  If he drew enzymes at 4 pm would anything have registered since he had a normal 12 lead and barely any symptoms?

[CCF HeartMD6]

The ECG is a useful tool in the evaluation of chest pain -- but is only one part of the overall assessment. There can be certain situations in which the ECG does not reveal an underlying heart attack including (but not limited to):

- NSTEMI (non-ST elevation MI)
- coronary vasospasm (in which the ECG only transiently reveals ST elevations)
- recanalization
- silent ischemia/infarct (most often occurring in the left circumflex)

It is always essential to use all parts of the history and physical examination in combination with the other objective data that is available (cardiac biomarkers, echocardiogram, etc).