I had the "pressure in the chest" thing once years ago. I finally went to the doctor, who ordered a bunch of tests including a stress test. Passed with flying colors. Turned out that I had an inflammation in the connective tissues where the ribs met the sternum (arthritis?). Any way, he gave me a prescription for anti-inflammatory meds and it went away never to return.
I never want to take one of those stress tests again, though. They hook you up with all of these electrocardiogram leads, then put you on a treadmill to get your heart up to a certain bpm. Then you're supposed to jump from the treadmill onto a cot that's positioned immediately at the foot of the treadmill so they can run the ultrasound probe around to get their pics. Anyway I'm a big guy with long legs, and they had trouble getting my heart rate up. They kept turning the treadmill faster and faster, and I kept trying to keep up without breaking into a run (which they didn't want me to do), and I kept feeling my heels just brushing the damned cot behind me. I was scared to death I was going to bang my heel on the frame of that cot and rupture my Achilles Tendon, and the treadmill would spit me across the cot and out into the hallway! Finally, after what seemed like an eternity on the treadmill, the technician finally declared "close enough" and turned the thing off and did the test.
Funny thing, though. Remember way back when, during the VietNam war, they instituted the draft lottery? Well, as luck would have it, I was in the first lottery! My birthday was pulled as #14! Only thing I've won in my life! I think I got my draft notice that afternoon! So I report to the induction center for my physical. I'm in this line with a bunch of other kids, stripped down to our skivvies, going from test station to test station. So they do a chest x-ray, and then on to more tests. Next thing, this orderly comes out and calls my number, tells me to get dressed, and that the doctor wants to talk to me. So I go see this doctor and he's kind of evasive, and beating around the bush, and basically says that the war is winding down, they don't need that many soldiers, and he's going to give me a 4F rating. Well, I didn't really want to go walk around the hot humid jungle with a rifle and flak vest and heavy pack and helmet and have people shooting at me, so I'm thinking "Cool!" I hit the door running and never looked back.
Years later I'm married and have a couple of kids, and I decide maybe I should get a complete physical. Never had one before. So I call my family doctor and make an appointment.
Well, the doctor is doing his examination, part of which is to take a chest x-ray. Next thing you know he comes in the room wheeling this electrocardiogram machine, and says he'd like to run off a EKG strip. So he hooks me up and runs the test, then goes on with the rest of the exam.
At the end, during the consultation, he explains. He said that when he saw the chest x-ray the first thing he thought was that I had an enlarged heart. A sure sign of heart disease. So he ran the EKG to confirm it. But the EKG strip was perfect. He actually said that if he wanted to take a sample EKG strip to show a medical school class what a perfect EKG looked like, he'd take mine! But he was totally stumped about what he thought was my enlarged heart. He said he finally got out an anatomy book where they listed the ratio of heart width to rib cage width, then used dividers to step my measurements off of the x-ray. He said my heart size was perfect for my rib cage width, and that I was just a big guy!
I bet that selective service doctor was thinking that they better get me out of the building before I coded, otherwise there'd be a LOT of PAPERWORK!