tachycardia to bradycardia

My boyfriend of 22 years was diagnosed with an enlarged heart and congestive heart failure 4 years ago.  He is taking  20 mg of Metoprolol, 25 mg Hydrochlorthiazide, 20 mg lisinopril once a day.  The past two weeks he has felt extremely fatigued,  he has been sleeping 14 to 18 hours everyday he  says that he has no energy.  I have been checking his blood pressure and his pulse rate and his oxygen saturation. At times his oxygen saturation will drop to 89 , and he will have to use an oxygen tank to help him breath. After using the oxygen for a little while his oxygen saturation will come back up to 98, and he will put away the oxygen until the next time he needs it. His blood pressure has been in the range of 153/93.   His pulse rate changes minute by minute going from 38 bpm to 142 bmp when he is at rest. Is this much fluctuation in the pulse rate normal?  

[Yvette BG]

Hi Kim,
I think it's a good idea to post this question to the doctor.
Good luck,
Anita