I m a 26yr old male, healthy, 160lbs, I have this issue since one week. Only happens when I am at a resting heartbeat, 72bpm or so, I get a sudden fluttering feeling from my heart and it also feels pounding, I can feel it if I touch my chest. It also causes an instant shortness of breath and a weird uncomfortable feeling in my upper airway, that feeling like you have to cough, so if I cough this whole episode stops and goes back to normal, but if I resist the urge to cough it will keep going.