why does my left arm becomes numb from shoulder joint to my fingers when i wake up?

Mayo,

Thanks for your question.

Your symptoms do not sound related to your heart disease, and are probably not related to you cholesterol numbers either.

It sounds like you may be compromising the circulation to your arm during your sleep.  You may be doing this by the position you sleep in, arm twisted around your neck, sleeping on an arm, or some other position related cause.  One strong possibility is nerve compression that is occurring during sleep, again most likely cause by positions your body takes during sleep. 

Locations for the nerve cause can be in the neck/cervical spine, the brachial plexus (a major nerve bundle/complex located deep in your shoulder.  Arterial compromises can occur around the should (subclavian artery), upper arm (brachial artery). 

In rare cases, a person can have an extra rib, called a cervical rib which can compress the subclavian artery and cause symptoms.

I suggest you make an appointment with your doctor to go over your symptoms, undergo an examination, and disccuss possibilities.

I hope this has been helpful.

Martin Cane, M.D.