like you, examinations showed no imminent arrest nor heart problems, although I do have a heart murmur
so that made me scared when I felt the fluttering, like a bird was flying in my chest, along with choking sensation in my throat. These symptoms are classic Panic Attack. I was given various medications, such as Propanalol which calms and slows the heart rate, on a need to take basis. Then was prescribed Cipralex (Escitalapram) - a longer acting anti depressant effective for anxiety.