I'm going to go with liver failure as my guess.
RIP Pat. I grew up watching Giants games on CBS.
Before he was a broadcaster he was the Giants kicker . Also was great doing the USA Open for years.
Summerall was an alcoholic by his own admission and gave up drinking quite awhile ago.Being with John Madden all those years im sure made him go to drink. Being a giants fan I really do miss hearing Summerall and Madden broadcast.
He had a liver transplant from a 13yo a few years ago.I'm going to go with liver failure as my guess.
RIP Pat. I grew up watching Giants games on CBS.