The surgeries, which are continuing today, marked an historic moment for health in Tonga.
Matangi Tonga reports the patients, aged between 77 and 90 years, had already had pacemakers inserted but need to have them replaced.
The surgery team is part of an organisation called Pacific Island Pacemakers Services.
Sione Latu, Cardiologist at Vaiola Hospital, said normally Tongans had to travel overseas to get the same pacemaker procedure done at a high cost.
