By Matt Hladik Arizona Cardinals defensive lineman J.J. Watt shared some scary personal news moments ago. Watt tweeted that since he is anticipating this being reported later today, he wanted to reveal on his own that he went into atrial fibrillation on Wednesday and had to have his heart shocked back into a normal rhythm Thursday. “I was just told somebody leaked some personal information about me and it’s going to be reported on today,” Watt wrote. “I went into A-Fib on Wednesday, had my heart shocked back into rhythm on Thursday and I’m playing today. That’s it.” As Watt said, expect to see…