6 Year Old with Premature Atrial Contractions on singulair

Hi,

I was wondering if there have been any finding regarding Singulair causing premature atrial contractions.  My pediatrician made the finding at a routine sick visit.  My son had never had an irregular heart beat before.  He has been diagnosed w/Asthma but the only med he is on daily is Singulair.  It has helped him tremendously...but I am concerned about the PAC's.  He has a complicated history w/ECMO for 9 days after birth and pnuemonia (pneumonia)/respiratory issues during cold and flu season. He was a full term baby.   As I said, I credit the singulair for keeping him out of the hospital for the last year and a half...but wonder if it also could have caused the PAC's?
Thanks,

[Cleveland Clinic]

I don't think that two are related in any way.  Singulair does not have any symptathomimetic activities so I doubt that it's causing the PAC's.  They may be related to his asthma and underlying lung process, be it inflammation or bronchospasm.  I would not be overly concerned about them unless they are becoming more frequent or causing him to feel palpitations.