new symptoms

Just wondering,
I've had my pacemaker in for about 15 years now, about to get a new 3rd replacement. Dr says i have about 6 months battery life. Question is, I have recently started experiencing pressure symptoms on neck and head. They usually happen when my head is down, with exertion or sometimes when I lay down. I feel pressure in my head, my face gets red, veins on left-side of neck start pulsating. My left shoulder and arm have also started hurting, sometimes feel weak. A couple of times i have woken up with my face being swollen. Also when i am having a conversation my voice gets hoarse and start to get short of breath. I am always short of breath just going up stairs. Sorry this is so long but these are all new to me, I feel like something is wrong when I explaind to PM tech, he said it was not related to it. But after reading these forums, Pacemaker Syndrome?, ThoracicOutlet Syndrome? I'm convinced it does???
Please explain.

[Cleveland Clinic]

You could be developing an occlusion around the pacer leads.  It would be unusual this far out but it's possible.  This would be consistent with an outlet syndrome.  Pacemaker syndrome is unlikely in your case.  It's related to pacing in the ventircular channel only.  I would get an US of the Left upper ext to rule out clot.