Hello. I had to call for an ambulance on Monday and was diagnosed with Tachycardia. They couldn't find anything else wrong in the ER and sent me home. Since Friday I have been experiencing heart palpitations, diarrhea, shakes and fatigue. I try to lay down and sleep but can't because the symptoms come in waves. The episodes last for about an hour, then I might have a half hour symptom free. Am I just having panic attacks?