dizziness

I am 35 year old female.  In November told have pvc's.  Had a holter moniter, stress test, ekg, and cardiolite stress test, and echo.  The results of these were normal, (stress test had non specfic changes, hence the thallium test). I would have good days and bad days with varying numbers of pvc's.  I am now 28 weeks pregnant and for the past month I have had some spells where I feel a hot rush to my face and feel very lightheaded)kind of like I may pass out)  The last time I had this it seemed like I couldn't feel my pulse, but it must have been beating as i didn't pass out. Other times it seemed like my pulse was fast but there. I think these spells last about 30 seconds or less( I never timed them) Then my pulse is beating hard.  these fighten me very much and I am scared that I am going to die before I get to have this baby.  I am going to see the doc that did the other tests again, when ever that is.  It seems like everyone except me is unconcerned.  Is this something very serious?  Could this be vt and isn't that a fatal arrhythmia? Please help.

[CCF-M.D.-CRC]

Dear sambo,
Dizziness during pregnancy can be due to a variety of different things.  There are fluid shifts and electrolyte changes that occur during pregnancy and this is the most common cause of lightheadedness.  It would be less likely to be VT but the only way to exclude this is to get a ECG during an episode.  If you are continuing to have these episodes I would discuss getting a Holter monitor test with your doctor.