One of the frustrating things regarding exercise and thoracic aneurysms is that there seems to be very little in the way of solid guidance. I suppose it's because everyone's physical fitness is different, our aneurysms are of different sizes, locations, and shapes, and hard and fast rules are tough to establish. The one that I hear everywhere is don't let your blood pressure spike, so no heavy weight lifting, nothing that makes you grunt and hold your breath. Regarding running, I've heard the same thing as you, keep your heart rate in the 120s and 130s. I have a couple of 4 mile loops in my neighborhood, so I've been walking the first mile, jogging the next two (ten minute mile pace) and then walking the last one. As a reference, I used to run 5-6 miles at an 8:20 pace with a heart rate in the 150s. I blame metoprolol for slowing me down so much but then I'm getting older, too. My aneurysm has been stable at 4.8cm for a couple of years, so my exercising does not appear to have had an impact there. Maybe I could push my exercise routine a bit more, but I have decided to err on the side of caution.

The INR you asked about stands for International Normalized Ratio, a way of measuring blood clotting. One "gift" I got from a mitral valve replacement four years ago is a combination of arrythmia and afib, so I am on a blood thinner (Coumadin) to avoid clots and, hopefully, a stroke. I think a normal INR is around 1.0, give or take a tenth, but they want mine to be between 2.0 and 3.0. I require a monthly check to ensure it's within range. It sounds like thankfully that's not a concern for you.

I joined three Facebook groups you might want to check out: Aortic Athletes, Cardiac Athletes, and Aortic Hope. There are some inspirational stories on them as well as tips that I have found helpful.