From: "Todd Moody" <[log in to unmask]> In the past 20 years I've had 4 or 5 epistodes of SVT, or "superventricular tachycardia". I'd suddenly feel my pulse accelerate and become "shallow" A friend of mine used to have these episodes and they ascertained that it was her thyroid. I don't remember much about the technical details, just that she would get a "shot" from her thyroid once in a while. Go figure.... Oliva