Thank u for responses. Yes Ive had lots of ecgs, echoes, holter monitors. I used to get thousands of ectopics a day, but had an ablation 3 years ago. For about 3 years is how long I've had the 'heart attack' symptoms. Left sided squeezing, gripping in the chest, arm pain, back pain, lightheadedness, nausea.. I get episodes of these symptoms at various degrees. Frightening, but have been to ER quite a few times and they don't know. Only once had a mild troponin rise.