Yes...sure it can...but by abnormal, it'll probably only be a tachycardia (i..e fast heart rate)...there shouldn't be too much problem with the rhythm or anything.
Yes, I have had panic during an ekg and it showed sinus tachycardia......basically a fast heart rate, very common in a severe panic attack. Hope this helped.
Hi Jerry- The previous posters are correct about the tachycardia.... I saw your post on another board and replied. Don't know if you saw it or not so I cut and pasted it for you here:
The standard 12-lead electrocardiogram is not always definitive for heart disease, if that's what's concerning you. Some individuals with no heart disease may produce an abnormal EKG. Further testing may be required to rule it out....Additionally, a person with significant heart disease may produce a normal EKG!
Findings should be interpreted in the context of other cardiac risk factors.
But to answer your question more directly, I'm not sure what the doctor meant by 'abnormal" but anyone who experiences anxiety/panic has an outflow of stress hormone (adrenalin)...
This can cause fast heart rates (there's your tachycardia) and possibly premature atrial or ventricular beats( palpitation, skipped beats, etc.), which would show on the tracing.
"Abnormal" doesn't necessarily mean there's a disease process going on. Again, it depends on what the docs are calling "abnormal".
I was once told my EKG was "abnormal" and it was simply because I had tachycardia.
Panic Attack during EKG 
