This case brings up a number of important points:

i) Bad data in = Bad data out ... Resolution of this tracing is extremely poor. As a result, it is not unexpected that computerized assessment of poor data may also be poor. In an "ideal world" — somewhat better resolution should be sought when purchasing ECG machines.

ii) Computerized ECG interpretation CAN be useful — IF they are used correctly. But clinicians need to be aware of what the computer can and cannot do well. I present my approach to optimizing use of computerized ECG interpretation in my ECG Blog #126.

iii) The ECG is neither sensitive nor specific for the diagnosis of atrial enlargement (especially for diagnosis of left atrial enlargement). As a result, I favor underdiagnosis of atrial abnormality. My degree of certainty about P wave widening on this poor resolution tracing is not high. As a result, I probably would not indicate “LAA” — though I realize others may differ. My approach to assessing for atrial abnormality is reviewed in detail in my ECG Blog #75.

iv) Complete RBBB is present on this tracing for the reasons Dawn mentions. That said, we LACK a history in this 74-year old man. While a history is always essential for optimal clinical interpretation of any ECG — it is especially important in this case. That’s because there are some subtle findings that could potentially be significant! In both lead I and lead aVL — the J-point (that occurs just after the wide S wave in these leads) looks like it might be slightly elevated. In lead II, the J-point and beginning of the ST segment look like they may be slightly depressed (which therefore could potentially reflect a “reciprocal” change). And in leads V5 and V6 — the ST-T wave is clearly flat, whereas we should normally see a definite upright T wave. Finally, there is still some T wave inversion in lead V4 — whereas normally with RBBB, ST-T depression does not persist this far over in the chest leads. NONE of these changes are definitive. ALL of them are subtle — but taken together, this makes 6 out of 12 leads that are not as expected for a simple complete RBBB in a patient “old enough” to have something (74 years old) — and seen on this ECG that is of extremely poor resolution. BOTTOM LINE: Clinical correlation is essential for knowing how to interpret the above ECG findings on this tracing. IF the reason this ECG was done is new chest pain — then the onus is on us to determine IF an acute event might be in progress.

I would like your opinion on medicolegal aspect when ECG interpretation wrongly says ACUTE MI. Many thanks!

The ECG machine interpretations are notorious for being inaccurate and they certainly create a problem when they suggest a finding that actually does not appear in the tracing. A clinical history is vitally important in the interpretation of any 12-lead ECG, and rhythm strips too! I pity the cardiologist that has to overread ECG after ECG, often days after they were done, and with no idea why the ECG was ordered in the first place. As complex and fascinating as it is, the ECG remains an adjunct to the human brain.

I would certainly want to know if the patient had chest pain at any point and also if the RBBB was present on previous ECGs. If he had chest pain and there was no prior history of RBBB, then the possibility of a very proximal LAD occlusion must be entertained.

In addressing the medicolegal aspect, the treating physician will have more support from the history, the physical exam, biomarkers and his/her own (hopefully) educated evaluation of the ECG tracing to support a reasonable opinion regarding the diagnosis. Those factors will be a lot more defensible in court than simply relying on a machine interpretation that is KNOWN to be unreliable.