From Paul's official site:-
During sound check yesterday, my heart spontaneously jumped to 190 plus beats per minute where it stayed for over an hour necessitating paramedics to start an IV and give me a shot to momentarily stop my heart and get it into a normal pattern. Not knowing if this episode was life threatening made it even more exhausting. After consulting with both the paramedics and a cardiologist at Cedar Sinai, they confirmed my worst fear. They said that I would put myself at risk if I tried to do the show.

I’m very proud of Gene, Tommy and Eric for carrying on without me. I apologize to anyone I disappointed and I’ll make it up to you when I see you again.

Paul.