TMZ is reporting it was a heart attack that killed Paul Bearer on Tuesday, March 5, 2013. Citing Bearer's son Michael, TMZ reveals Paul's death certificate lists the cause of the heart attack as supraventricular tachycardia or SVT -- a dangerously high heart rate.
SVT is actually quite common and usually isn't deadly. However, the symptoms are common and include anxiety and heartburn and can sometimes go untreated. This is likely what happened in the case of Paul Bearer as he suffered from SVT in the final weeks of his life.
Bearer, whose real name was William Moody, was only 58.