@silverkat Hi welcome to Connect your feeling of flutter reminded me of something similar. I was never sure what to call it but mine was like a pounding feeling when I laid on my left side. But seemed fine on my back and right side. I mentioned a few times to the cardiologist back then (since I'm breaking in a new Heart now) . But just was told it was maybe the way I was laying. Not sure if that is similar to your concerns. Mine I think may have been due to my heart being enlarged. Thus more noticeable since it was pushing on areas that could feel the beating. If it gets really troublesome maybe the doctors can do.a.halter test to try and capture the event. Mine never really lasted long periods except when in that position.