Doctors said the procedure had gone well, but Netanyahu, 73, would remain at the Sheba Medical Center in Tel Aviv for observation.
Netanyahu had been admitted “because of what we call transit heart block,” Dr. Eyal Nof, a cardiologist at Sheba, said in YouTube video posted by the medical center.
He added a heart monitor, which was implanted in Netanyahu just over a week ago when he was rushed to hospital with dehydration, had alerted them to the problem.
The data indicated that Netanyahu needed an “urgent pacemaker implantation,” Nof’s colleague, Dr. Roy Beinart, said in the same video.
“During the night we implanted a pacemaker,” Nof said. “All went well. The prime minister is doing very well.”
A spokesperson for Netanyahu’s office said the procedure was “successfully completed” and the prime minister was “feeling well.” They said he would remain at the hospital for observation and he was expected to be released later today.
The prime minister’s office said that justice minister Yariv Levin would stand in for him while he was under sedation. However, the weekly Cabinet meeting scheduled for Sunday morning was postponed and two upcoming overseas trips, to Cyprus and Turkey, were being rescheduled, Netanyahu's office said.
His procedure came after hundreds of thousands of people took to the streets across Israel on Saturday night to protest of his plans to overhaul the judicial system.
It came after thousands braved the blistering heat to march from Tel Aviv to Jerusalem on Friday, many of whom then set up tents which remain in front of the Knesset, Israel’s Parliament in Jerusalem.
In a video from his hospital room on Sunday afternoon, Netanyahu, wearing a white dress shirt and dark blazer, said he felt fine. He said he was pushing forward with the legislation but also pursuing a compromise with his opponents.
“In any case, I want you to know that tomorrow morning I’m joining my colleagues at the Knesset,” he said, without saying when he would be released.
Lawmakers nonetheless convened inside the Knesset on Sunday to debate the bill that would curtail the Supreme Court’s oversight powers by limiting its ability to strike down decisions it deems “unreasonable.” Legislators will vote on the bill on Monday.
While the overhaul is supported by Netanyahu’s hardline, extreme-right, religiously conservative allies in his coalition government, critics say removing the standard, which is invoked infrequently, would allow the government to pass arbitrary decisions, make improper appointments or firings and open the door to corruption.
Opposition to the deal includes many key institutions of Israeli civil society, including the national labor union, its medical association, military reservists, fighter pilots and business leaders.
Israel's military said Friday that over 1,100 air force reservists had co-signed a letter threatening to stop volunteering if the government goes ahead with the reforms and over 100 retired security chiefs including Yossi Cohen, the former head of Israel's spy agency Mossad, have spoken out against it.
On Monday, President Biden urged Netanyahu to reach a broad political consensus on the reforms before passing any legislation.
Netanyahu’s government has already approved key portions of the bill, though it has to pass through the Knesset to become law. The overhaul could prove crucial to keeping Netanyahu himself out of jail, as he faces a litany of corruption charges on bribery, fraud and breach of trust.
Netanyahu has suffered from several bouts of ill health during his record sixth term as prime minister.
As well as last week's hospital stay, he was also hospitalized in October after feeling ill during prayers on Yom Kippur, a day when observant Jews fast.
Paul Goldman reported from Tel Aviv and Leila Sackur from London.