@megansims Yes in a way I had a similar experience, not those exact hours and my issue was Ventricular Tachycardia of the lower chambers
But almost always my episodes happen between 10 pm. and 12 to 1 am. Not every single one but probably 80 % of them. And it almost always while sleeping mostly towards the end before transplant. It may have something to do with sleeping or lying down but I did also have some while driving in the earlier days. Nothing ever confirmed by medical personnel except that it appeared to be true. I do know one other aspect I learned early on in my heart issues. It's more work for your lungs to breathe lying down than sitting or standing. So it may involve something along those lines also. I'm also a cpap wearer and I do know sleep apnea does affect heart function. Have you been tested for any sleep disorders?