Question:

I don’t think I had a heart attack, but my EKG suggests it. Please explain the result.

My EKG resulted in sinus rhythm but possible inferior or anterior infarct – age undetermined. I am 61 years old, Hispanic woman and there is no history of heart disease in my family. I weigh 148 lbs and do not smoke or drink alcohol.

Submitted by Maria on 04/23/2015

Answer:
by Raymond F. Stainback, MD

This question comes up frequently, almost on a daily basis in patient care with regards to the ECG: A patient with no history of coronary artery disease with no previous symptoms and perhaps also even with no significant cardiac risk factors has an ECG interpretation suggesting prior heart attack (myocardial infarction or MI). There are occasions when the ECG is correct and the patient did have a previously unrecognized “silent” MI. More commonly, the ECG reading is a “false positive” interpretation. In other words, even though the pattern of voltage readings on the ECG has the appearance of a prior MI, in fact, the heart is normal &there was no MI. This is because to get a normal ECG tracing, the leads placed on the chest wall have to be on a certain “normal” distance from the heart muscle within the chest. It turns out that normal people vary greatly in the direction that the heart is positioned in the chest. So, even if the lead position is correct on the chest wall, some of the leads may be pretty far from the standard distance &the recorded signal can be too small, giving the appearance of a prior heart attack (decreased muscle voltage signal). The other thing that can cause this is if the technician accidentally places the leads in the wrong spot. This difficulty can be addressed by getting an echocardiogram or other imaging test to establish whether or not the ECG was correct or a “false positive” for MI.