Without knowing anything about you, your history, your medical history, new workups by physician specialists, my guess is that you have begun to slip somehow and you're heart is letting you know it's working too hard when you are at rest, especially when you are asleep and your heart can kick back and unlax for the night. If I were your earnest physician, I would order blood assay, pulmonary workups, kidney assessment, liver assessment, cardiac assessment, and probably suggest very, very, strongly that you should consider an over night sleep lab....a polysomnography....to see if you have undiagnosed, and very dangerous, obstructive or central sleep apnea....or the dreaded combo called 'complex sleep apnea' where both of those intruders are resident in your body.

You need a concerted and serious look at your overall health picture. Your heart is already heading towards arrhythmia, which the palpitations warn of (I'm assuming they are just bigeminal/trigeminal PACs/SVTs, which you can look up or ask your PCP or cardiologist about). If you are experiencing nocturnal atrial fibrillation, and it doesn't wake you up (how do we know it isn't that and that you head to the can because many patients find they need to pee as soon as their hearts begin to fibrillate! Yes, it's actually a thing!). If you ARE fibrillating, even for a few minutes, your risk of a stroke climbs, almost five times what it was an hour earlier. Your cardiologist would want you on a direct-acting oral anti-coagulant right away, taken twice each day usually.

Please see a physician right away.