Quick update: both the routine test and the stress test (6 minutes on a bike with gradually heavier load) gave perfectly normal results for my age. I felt no discomfort during the test. The cardiologist is 99% sure it's not related to my heart, but ordered a CT scan with contrast material anyway to rule it out 100%. Blood pressure in rest is 112/79, only thing that puzzles me is a slightly higher RR (75 where I used to see 50) - but that could be stress/panic related.

As I'm lucky (in a way) I can have the CT scan in a few hours. After that, it's probably a sleep study, but both docs agreed with tapering down the Elavil (well, it's Redomex in our neck of the woods), and the cardiologist suspected it might be involved, or have an effect on whatever is wrong with me. As did the GP.

Blood panel was absolutely fine, and I was surprised to see B12 at >1000, even though I only take a 5mg methylcobalamin tablet every 2 to 4 days. More proof those tablets work perfectly fine, are safe, no injections needed etc. Some values (like hematocrit that was way up there 2 years ago still) have dropped spectacularly since I stopped smoking 2 years ago (and yes Mrs. D., still stopped.)