Heart palpitations on water fast

Hello .I am doing a Water Fast and I am on on 7th day of it .I was alright til yesterday when i experienced a two second palpitation.
Then today i had a racing heart that continued for a few minutes but happened most of the day.I am scared of continuing the Water Fast .I am drinking 4 liters of water a day and resting .
Also i have gone two months ago to the doctor and ecg showed fine and also done blood tests and they showed fine.
My question is .Am I safe to continue this Water Fast ?Do heart palpitations go after a few days or i should quit?
Thank you all