It could be. Apparently estrogen increases the amount of time "long "qt" between beats and progesterone reduces it. With menopause the balance of the two can get out of wack and cause long QT.

But, that being said, don't let a doctor just write it off to that. Far too often they just say something like that. If it isn't right for you find the cause. There was a good blog I read that was just devoted to this.. called "life off beat".