FAA Flight Physical  

If you want to find out earlier rather than later for any cardiac problems then just getting an EKG during a 1st Class medical will not provide that. Failing the EKG only indicates that the problem started long ago and now you are dealing with the results of that problem. You need to see a cardiologist and get a nuclear stress test and other imaging such as a PET scan or MRI. Only then will you know if you have any forth coming issues that need to be addressed now rather than later. I know many pilots who did this and found out that they were dealing with serious issues before having a heart attack or other disqualifying complications. If you dont care then get a 2nd class because it is cheaper but the resulting information is the same.