Atrial Fib with HR of 214

[sueinns]

I am asking this for a friend who has atrial fibrillation and takes a beta blocker.  This person is quite athletic and recently had a stress test.  He felt great but it was stopped because his heart rate reached 214.  Said he felt no symptoms that his rate was that high.  He now has to wear a holter to rule out anything serious.  Apparently, while on meds, his heart rate with high exercise shouldn't exceed 140.

Any ideas on this?  How high can a heart rate go, particularly those with AF.  Is there such a thing as having a superimposed trachycardia with an AF?  

[caregiver222]

To have permitted him to exercise with a heart rate above 170 is irresponsible. It is asking for conversion to ventricular fibrilation. Plan stupid. I wonder, however, whether this was his heart rate or the EKG rhythym, which are not always the same. You can have an EKG heart rate higher than your actual heartrate. Rare, but not impossible. Often atrial fibrilation can be moderated by taking magnesium glycinate. Consult your cardiologist for his recommendations on this.

[discobeat]

They always stopped me at 190, which I hit with a brisk walk.  I have a-fib, so to check the heart at full stress, I would go jogging with the holter on.  It was quite normal for me to keep at 186 for the entire hour long run, with spikes up to 210 when I would sprint, and I take calciam blockers and dig.

Best way to think of it is, If it doesn't feel bad when you are doing it, it probably is normal for you.