Aubergine,Hello and welcome to HealingWell. How is your recovery coming along? For the procedure you had, it seemed to me you were pretty much on track the day of your surgery.
Considering you had a cardiac procedure and underlying osteoarthritis it would not be unusual for you to feel weak and tired. Spread out your activity and rest and do not be afraid to call your Dr. if you feel you have a question that requires a physician's assessment.
Blessings,
Kitt