How much can I exercise after possible heart attack

Jan2 I was taken to E.R. The end result is troponin levels at 33 but normal ekg, echocardiogram and heart cath. MRI shows possible scar tissue. I was put on precautionary beta blocker, statin (even though good cholesterol) and aspirin regimen. I am a runner (marathon in 10/2011) and feel fine doing run/walk intervals of at least 5 miles but Dr said I should do no more than 1-2 unless the second read of MRI shows all is clear. The puzzle in this picture is the elevated troponin levels. I was only in hosptial for 1 night and have continued all other normal activies. Should I get another opinion for rehab? I would like to run my next half marathon the end of March.

[ed34]

Why was you taken to ER?  chest pain?

[dfritsch]

Yes, I had chest and jaw pain. The ekg was normal but my heart enzymes shot up. They think it may have been a spasm of artery because echo and heart cath showed no blockage and heart performing normally.