Disgraced Peruvian former president Alberto Fujimori was rushed to hospital from prison after suffering from a heart problem, his doctor told AFP on Thursday.
The 83-year-old, who is serving a 25-year sentence for crimes against humanity committed during his presidency, underwent heart surgery in October.
"He decompensated at seven in the morning and started experiencing an irregular heartbeat," said Dr. Alejandro Aguinaga.
Fujimori's condition has since stabilized, Aguinaga added, noting the irregular heartbeat was linked to the ex-president's operation five months ago, when he had a catheterization and a stent fitted after suffering from a racing heartbeat.
His daughter Keiko Fujimori said at the time that one of his arteries was "70 percent obstructed."
Fujimori -- president from 1990 to 2000 -- was jailed in 2007 but has long suffered from breathing and neurological problems, as well as hypertension.
His family has appealed to courts several times to release him on health grounds.
Fujimori was jailed over two massacres committed by army death squads in 1991 and 1992, in which 25 people, including a child, were killed in a supposed anti-terrorist operation.