I have suffered with heart palpitations since I was a teen, and I’m now 75. I have had attacks that have lasted over four hours. I was in my thirties by the time the attacks got that bad. When I was a teen the attacks only lasted a few seconds or minutes. After a four-hour attack I went to the hospital for a test and then wore the monitor. The doctor said I had mitral valve prolapse. He prescribed medication. For several decades that medication kept it under control.
When I moved here I got a new cardiologist. He said I only had high blood pressure, not mitral valve prolapse. He changed my medication and everything was okay for several years.
Then last year I had a blood test and my primary care physician adjusted my thyroid medication and my heart went nuts. This led to many more tests, wearing a different monitor, and experiments with many medication combinations. Meanwhile, I was afraid to go anywhere alone in a car for fear of blacking out, even though the doctor said I wouldn’t. He said my heart had an electrical problem that would be taken care of by surgery if we couldn’t control it with medication. Fortunately, it seems to be under control again now. It seems to be tied to my thyroid. If I get more thyroid medication than I need, the palpitations come back.
I agree this is a scary condition and the episodes are frightening. But if your problem is electrical, like the short circuit in my heart, surgical help may be available. I hope you find a solution that works for you. You also might want to see an endocrinologist to make sure your thyroid is as it should be.