I had all the heart related tests too. Not cardiac related. Mine has lessened over the last few months to maybe 1 or 2 a month and then only about a 2 on scale of 1-10. I do take cholesterol meds and that depletes the body of coq10 so I started taking that several months ago. It is more annoying than scary for me and I might add also that I had a sleep apnea test done couple years ago only to see if it would pick up anything but it didn't. It did show I had mild sleep apnea and I have a nasal cpap. I used it religiously for first 6 months then slacked off. I might use it now about 4 times a week. Not sure why the vibrations have all but stopped but after having them for about 4 or so years, I'm not complaining. I might have 1 or 2 a month in the torso or pelvic area but that's it. I may add though that the upper rib area on both sides of my back has been very painful for a few months. Almost like I overworked those muscles. I have an MRI scheduled next month for back issues. I honestly believe it's a neurological issue with a certain nerve to do with the brain. Ask about a sleep test to see if it'll pick up something, mine didn't though. I also wore a heart monitor for a month and it didn't pick up anything either. I have palpitations bad and had to press a button whenever I had one. Although it seemed like I had a lot of them, he said I only had them 1% of the time. I take 1000mg of magnesium too. Cardiologist recommended it and they have been almost non existent for a few months. Hope you find some answers soon. Nothing like feeling like you have swallowed a vibrator. Also, it's the vibrations that wake people up. Most say they have them upon waking etc but it's the other way around. The vibrations are so strong that they wake you up. Used to, I could turn over and they would go away. They were worse when I lay on my back.