SVT in pregnancy

I am a 39 year old female. I am 10 weeks pregnant.  I had SVT prior to pregnancy, under control with metoprolol.  This past week, my 10th week of pregnancy, the SVT has been out of control.  Should I be worried about my health, or the health of my unborn baby?  Is there anything I can do?  All my cardiologist said was that he didn't want to start me on any new meds in pregnancy, and he didn't want to increase my dose because he didn't want my BP to get too low.

[tlk2000]

I had SVT during my pregnancy 8 years ago.  I had several episodes of racing at 230-255. Some would last minutes others would last hours.  My doctor prescribed blood pressure medicine (I was not previously on them). I also saw a homeopath who recommended GABA and Taurine.  I used chiropractic care to help with relaxation and would notice a drop in heart rate after adjustments.  It was very nerve wracking, but after a time my episodes became less and less frequent. My baby was born healthy at 41 weeks.

I'm assuming they checked your thyroid levels.  A couple of years after my daughter was born, the episodes came back and I was diagnosed with WPW syndrome.