My issue started the day after my 37th birthday. I had an attack which felt like I was having a heart attach. My check was tight and my heart seem to drop (to the point my adrenalin kicked in). Since this I have been having issues where my resting heart rate will slow down to 55 (meaning I will drop into the 40's at night). I seem to have cycles where this occurs every 2 months and the issue will last for 20 days or so. The issue seems to switch on like a light switch and switch off. When I am in a cycle, I get dizzy, wake up gasping for air, feel like fainting. I also seem to burp a lot as well. My last episode gave me sever pains in my abdomen which seem to move from my left side to the center and over to the right. I have gotten a CT scan which has come back okay, MRI of my brain, EKG, heart monitor for a month, blood tests...etc all came back okay and normal. I did have a stress test where my blood pressure did drop to 88/40 once I got off the treadmill, but I was also taking Niacin which I believe was causing my blood pressure issues. Since I stopped taking it my blood pressure issue seems to have stopped. I did just have a endoscopy which did discover that I do have an ulcer at the base of my stomach and esophagus. I also have h-pylori bacteria. My question is would an ulcer cause these symptoms to cycle like I have or could this be a sign of something else like vagus nerve issues? Any help would be greatly appreciated.