At 6 weeks my babies heart beat was at 95 and it was concerning but only if you go back and it doesn't go up do u need to worry some ppl dont get a heart beat that soon
A heart rate of 178 would be more in line with a pregnancy of 9-10 weeks, so that is not a good comparison for your situation. I am assuming you will have a follow up with your Dr or midwife? Be sure to discuss your concerns & meds with them, but I don't think the heart rate shows anything concerning at this point. Like a pp said, some 6 week ultrasounds don't even detect a heart beat, so be positive.
www.ob-ultrasound.net
According to this site, among others, normal heart rate around 6 weeks is 90-110 beats per minute? Sounds like you got a pretty normal estimate? Good luck! :-)
Pain meds can lower heart rate. 111 is very low. My daughters 1st u/s hr was 178.
I've had to hold my breath before. If the doc didn't show any concerns then don't be worried about the heart rate. They'll let u know if something isn't right. Its always good when they can hear the heart at 6 weeks. Sometimes you can't.