I felt like electric shock like feeling which became sharp on my left chest?

I was having mild chest pains..So thought of taking some rest would relief that pain so I went to sleep..I was in a dream but suddenly I felt like electric shock like feeling which became sharp on my left chest like shooting pain and slowly relieved after few seconds what could that be?? Is that a heart attack ?? That happened Nly once ..I had my ecgs,2D echo scanning,stress test which all came out as normal ..Just a slight ST elevation (V4) in ECG where doctors said that it’s normal for young age