If your QT gets too long you could be at risk of arrhythmia. QTc is QT corrected for Heart rate, so if you’re getting that I’d definitely get it checked out, although there are individuals who have a slightly prolonged QTc for no apparent reason. Better be safe though.

I can’t view the other comment, but the QTc prolongation that you describe is very likely due to an under-correction for heart rate. QT is exquisitely rate-dependent and shortens as heart rate increases. However, due to the QT rate-dependence, a formula is used to approximate the QTc (QT corrected) at a reference heart rate, usually 60 bpm in man. It is not at all unusual for a generic rate correction to not work well, or at all, in a given person. Absent other danger signs which Frontier X has likely advised you on, your excessive QTc likely incorporates at least some rate-correction error. /hank