a regular dose. I had palpitations for 3 solid years about 4 years ago (saw a doctor , no diagnosis of a heart disease ). I stopped taking any and all medications while pregnant and having kids, during the last 4 years. The palpitations vanished entirely during that time. I took two tylenol today, and I m having palpitations again, pretty severe case of them. There have been two other mild occurances of them recently, and I may have taken tylenol, but am not certain. The only thing I can think of that s consistent between my old lifestyle and now is that I took a regular dose of acetaminophen .