Newborn with Long QT interval

[MommyOfParker]

My son was in the NICU the first few days of his life because he had a low heart rate (the lowest was 90). Although his heart rate stabilized in a few hours his EKG showed he had a prolonged qt interval. The cardiologist said it was caused by a medication I had been taking throughout my pregnancy.  At the hospital they did three EKGs. I just obtained his medical records today and im very confused. The first EKG showed a QTc of 485 (0 days old),  the second (1 day old) showed a QTc of 449, and the third (2 days old) showed a QTc of 459. The notes say the first EKG shows a prolonged QT interval and the notes from the second day say, "EKG shows QTC still prolonged" and the third note says his EKG is normal???? Why is 459 normal when it is longer than 449 which was considered prolonged? Is the range for a 1 day old baby different from that of a two day old? Maybe i am reading it wrong? Thank u for your help!

[CCFHeartMD 15]

Hello. Nobody can diagnose through internet but generally speaking, the normal QTc interval in newborns is less than 440 msec although it can be prolonged up to 470 msec in normal patients. When the QTc is borderline (440 and 470 msec), it is suggested to recheck the EKG overtime to certify the QTc decreased to a normal range. I can not explain why the doctors changed the report with a QTc of 449 msec and then when the next day was 459 msec as I have not seen the EKGs, but it may be related to the value given by the automatic report of the EKG machine (that should not be used to diagnose QT prolongation) and the measurement done by the doctor. You did not describe what medication were you taking when your child was born, as that information would help to analyze the initial slow heart rate of your baby and the QTc question. Finally, if you don't have family history of sudden death or long QT syndrome, it is most likely that the initial prolonged QT of your son was do to a reversible cause, but a follow up EKG is warranted. Good luck.

[spade22]

I currently know more about QTc intervals than I would like to know and am not going to attempt to answer this question  (thats what the experts are for)  however, I would like to say I have reviewed some of mommyofparkers older posts and in one post it states there is a strong family history of heart attacks on her side, and her babies fathers side and several family members have passed away from cardiac events in their 40's.  I think this information might provide more insight for the  cardiologist when he reviews this post.