some irregularity in heart beat can cause this type of problem ,
at present i would like to advice some tests ,
or family physician and get ECG , 2D Echo , and thyroid
profile test and if every thing comes normal and still your problem persist then go for 24 Hour Holter study which will give you details of heart beat in 24 hours ,
it self also cause this type of feeling ,
stay relax ,
eat healthy food and take your food in time .