I am 33 weeks pregnant and just got back from an appt with my OB. I have been having these spells for the past few months where my heart pounds, I get extremely light-headed and I feel like I can't breathe and I'm going to pass out. I had one of these spells where my heart rate went up to 130 at my Doctor's office and she told me that it was Maternal Tachycardia. I had never heard of the term until today. She seemed concerned and I am worried. Can anyone tell me more about it... dangers, causes, treatment, etc.? I am 24 years old and in good health. Not overweight and have great eating habits.