Hi Sweetie, my baby boy has an SVT which was diagnosed at 28 weeks gestation, after i kept complaining of him not moving (I'm so glad i was a kick counter) his heart rate was around 270-300 bpm too, and they said this is why he wasn't moving much as he was so tired from his heart racing. We had many scans and were told we were very fortunate he was not in heartfailure as if he was they would have delivered him there and then, but as i said we were lucky and he stayed put. The doctors prescribed digoxin for me, which slowed his heart rate to about 170 ish, like you i became ill with the medication but the doctors denied all knowledge of it being meds and asked me to continue with it which i did.
At weeks i went into labour and was about to have the meds to stop it when they said i couldn't have them as they would react with nathan's meds and i would go into heart failure so we were blue lighted to trelisk who had a bed and a cardio, luckily he stayed put but i was bed rest at home until he was delivered.
My Nathan was born by c-section at 36 weeks and he was fine but was taken straight to nicu for monitoring, he was fine until day 2 when the digoixn had fully left his system and he went back into SVT, but he was quickly treated with ice to his forehead which can be very effective but not in his case so he was given adenizone which worked fine.
The docs were going to start him on digoxin again but after consulting with a senior cardio at the childrens hospital they started him on propranalol (syprol syrup) which is a liquid beta blocker and does not need the same invasive monitoring as dig.
We brought him home at one week old, having had no further episodes They also did an ecg which showed an abnormality in the delta wave, doc said there is an extra wire in his heart which is throwing the rest into chaos. We had a follow up at 6 weeks by the senior pead cardio and were told he was well enough to just see the regular paed cardiologist, we saw him at 4 months old and then were told to go back in May, he had more heart scans and ecg's and he is fine. Since the initial ecg no abnormalities have been detected in the delta wave or anywhere else, i asked the doc if the medicine was masking it or if it had gone and he said it could have just gone but the best time to see the problem is during an episode or just after so that could be why it was not showing. We have been told to go back next may and one he is 2 in June his mediation will be stopped, at the mo i have been told to no longer increase it with his weight as they would like him to start outgrowing it.
We have been told that he may never have another episode in his life the chances of this are good as he has not had another episoide since the one in nicu, or he may have another episode somewhere around 10-13 years old and if this is the case they will insert a small catheter into groin and up into his heart and then they can burn the extra wire out.
Generally his prognosis is excellent and they are not at all worried or conerned and he is such a well, healthy little boy and a big bruiser i may add, the only way people are aware of his condition is if we tell them or they see us giving him his meds and they look closely enough to see it's not calpol. The doctors were very insistent in telling me he is not ill, and he should not be treated any differently from other children, they did say if he does have another episode when he is a toddler and cannot tell me he feels unwell to look out for him being lammy, going grey and if he is playing, he may stop very suddenly and need to rest.
They gave me a stethascope to listen to his heart rate, and when he came home i had to listen at every feed, then over a few months i cut it to times a day, now i listen one a week and don't need a stethascope as i can now hear just by putting him up to my ear, and the stethascope has started to bother him as he has got older so this works well.
I really hope that hearing Nathan's journey so far helps, i won't tell you not worry, you're a mum and you're baby is still inside you and has a problem, so of course you will worry, but my little boy is proof that it's not all bad. You are always welcome to pm if you ever need anything. Huge Hugs xxx
but now babys heartrate has gone back up last night it was 256bpm and again this morning 240+ 
