You must have a big heart there, my friend!
Joking aside, your pump needs to be pretty effective to supply enough blood flow and pressure to your body with only 30-40 pumps per minute. Seeing as you can raise it up to normal exercise levels without problems, I doubt there is any serious problems. However, I would like to see an ECG, preferably over 24 hours, to rule out any abnormal sub clinical rhythm patterns.
The symptoms at night in your extremities may very well be related to sub sufficient blood flow and pressure. Or a couple of hundred of other factors..