Hi. I suggest you to first get an ECG done. But as these episodes last for a short time, they are very likely to be missed on a routine ECG. Hence, you are very likely to need a test called Holter test where your ECG will be recorded continuously for 24 hours. Also get thyroid test done. But, as I always say, first get yourself thoroughly examined by a qualified cardiologist, discuss these investigations with him and then proceed. Hope this helps.
Dr Chandrashekhar Munjewar