Does riding on big swing which is operated by motor, cause any heart problem?

Heart: no scientific evidence. S answer is no. if some one already has a weak heart then may cause problems . Defiantly will not give rise to a heart disease.

Should not.: Your skin is a remarkably good electrical insulator at "low" voltages & pwr (i.e., less than 60V / 60 J), not to mention the other insulation applied to most industrial motors. It's unlikely any current will get through to your heart or cause any physical problems. Now, the gravity-defying aspect of a swing is another matter... if you have fear of heights, it'll get your heart pounding.