Since last 2 years, I'm having palpitations and transient jerks for 2 to 3 seconds in my chest which occurs every now & then but theres no fixed time when this jerk happens. Feel very awkward when this jerk occurs. I feel as if my heart has stopped for those seconds. I exercise regularly. But I dont feel any pain in my chest. My ECG, 2D ECHO, HOLTER ECG all reports are normal. I want to know the following:- 1. If I'm a patient having any cardiac blockage. 2. If these jerks are signs and symptoms of possibility of cardiac arrest or any other serious cardiac diseases. 3. If none of the above, then what is causing these transient jerks and palpitations in my chest?