Have you had an ECG or worn a holter monitor to verify a-fib?I am. If I were to lay down and try to fall asleep this very moment, I would wake up immediately with palpitations. Then I begin to feel pain around the upper chambers of my heart, as though they are fatiguing from beating at excessive rates. With that comes a spreading burning sensation through my skin. It's feels like cortisol or adrenaline is reaching the heart, triggering palpitations and then being pumped through the blood to the tissues and causing hot flashes.