Watt added that he would play in Sunday's game against the Carolina Panthers in Charlotte. The Cardinals pass rusher finished the game with three total tackles after playing 41 snaps.
NFL Network Insider Ian Rapoport reported that Watt was not feeling well on Wednesday, which led to him being examined by a doctor. The doctor determined that Watt's heart was not in rhythm, which led to the shock treatment.
Watt addressed the procedure on Sunday after the Cardinals' 26-16 win and insisted that he had been assured that it was safe for him to play.
"On Wednesday, my heart was beating weird, got it checked out, got A-fibbed so they can shock it back to rhythm," Watt told reporters. "Talked to cardiologists, electrophysiologists from all over the country. I was assured multiple times from multiple people that there's nothing else you can do, and I can go back and play like normal. Said it can happen again the next day, or it could happen never again the next 20 years. So I was assured multiple times, so I went back to practice Friday, practiced, and here we are."
Watt also expressed displeasure that his medical information was going to be reported. "The only people who knew are people I should trust," Watt told reporters.
Watt did not practice Wednesday or Thursday and was listed as questionable for Sunday's game due to a calf injury.
According to the Mayo Clinic, atrial fibrillation "is an irregular and often very rapid heart rhythm (arrhythmia) that can lead to blood clots in the heart."