Martz, who has been ill for more than a month and missed two practices last week while undergoing tests, was on the sideline for the Rams' 37-31 loss to the Seattle Seahawks on Sunday. After the game, which dropped the Rams to 2-3, Martz said he wished he had stayed home.
The 54-year-old coach announced last week that he was being examined for endocarditis, a bacterial infection of the lining of the heart or a heart valve. Martz said at the time that his condition had worsened and began taking antibiotics Friday.
Assistant head coach Joe Vitt will lead the team in Martz's absence. Players learned of Martz's status during a brief meeting Monday afternoon, but none would comment.
Martz spoke with a raspy voice but sounded optimistic about his health after Sunday's game. Still, he said that in retrospect, he should have allowed offensive coordinator Steve Fairchild to run the show.
Endocarditis affects 10,000 to 20,000 Americans each year and in some cases can require open-heart surgery, according to Dr. Arthur Labovitz, director of cardiology at the Saint Louis University School of Medicine.
Martz was first hospitalized Sept. 30 with what was thought to be a sinus infection. He coached two days later during a 44-24 loss to the New York Giants.
NFL coaches are notorious for their long hours, and Martz is no exception, sometimes sleeping at the office. And heart problems have affected relatively young coaches before in the high-stress atmosphere of the NFL.
Dan Reeves had a heart procedure while coaching Denver in his mid-40s. During the 1998 season, he underwent quadruple bypass surgery at age 54 but returned to the sidelines less than four weeks later to coach the Atlanta Falcons to the Super Bowl.
Dallas' Bill Parcells has had several heart procedures and cited health problems when he quit the New York Giants after winning his second Super Bowl with them at age 49 in 1991. He has since coached New England and the New York Jets as well as the Cowboys.
In 1988, Chicago coach Mike Ditka suffered a heart attack at the age of 49 and missed just one game. Two weeks later, in Washington, he was supposed to be just an observer, but ended up coaching the game.
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