Hey, stress raises blood pressure and one's pulse rate and these do not contribute to a healthy future. Inadequate sleep is a primary stressor for humans everywhere. In the process of healing and returning to a normal healthy routine, it is important to actually work to improve one's sleep. The simplest thing I know to do is to get some exercise. We all have different exercise tolerance but pushing just a little each day has some real benefits and one of the first of those is more restful sleep. Manage your sleep time, how quiet or dark your room and if these don't help you should discuss it with your doctor. One suggestion for me was to stop sleeping on a pillow...odd though it sounds, it helped immediately.
Some time ago, I learned rather to my surprise, that I have sleep apnea and for the past decade have used a CPAP device each night. All it does is keep the breathing passages open so one can breath normally after nodding off. Once I began using my machine, I found that I could exercise more easily. Sleeping soundly, restfully, I watched my blood pressure and pulse rate fall as I became more active. It is a kind of feedback loop - restful sleep > improved exercise tolerance > better sleep. Today, I still use my machine every night and I wake normally each morning feeling rested.
By the way, I too began having night sweats after my AVR and it is worse on nights when my sleep is disturbed. I can say that over time it has improved.
Sleep Well
Larry