Boone underwent surgery at St. Joseph's Hospital in Tampa on Wednesday. The Yankees announced that the procedure "went as expected" and that Boone is now in the hospital's recovery room.
"As many of you know, I underwent open-heart surgery in 2009, and I wanted everyone to understand where I'm at regarding the procedure that's taking place today," Boone said in a statement.
"Over the last six-to-eight weeks I've had mild symptoms of lightheadedness, low energy, and shortness of breath," he continued. "As a result, I underwent a series of tests and examinations in New York prior to the beginning of spring training, including multiple visits with a team of heart specialists.
"While the heart checkup came back normal, there were indications of a low heart rate which, after further consultations with doctors in Tampa, necessitates a pacemaker."
The 47-year-old also said he looks forward to returning to work in the next several days, and he completely trusts the Yankees' coaches, staff, and players to continue training properly during his short absence. General manager Brian Cashman told reporters that Boone participated in the team's daily video call from his hospital bed ahead of the surgery and filmed a video for his players and coaches.
Cashman added that Boone could potentially leave the hospital within the next 24-to-48 hours, according to ESPN's Marly Rivera.
Boone's surgery in 2009 was conducted to repair an aortic valve after a congenital defect was discovered while he was in college, reports Kristie Ackert of the New York Daily News.
The Bronx Bombers have won 236 games, a division title, and appeared in the playoffs three straight years since Boone took over as manager in 2018.
Bench coach Carlos Mendoza will serve as acting manager of the Yankees during Boone's absence, according to Joel Sherman of the New York Post.