Former Emperor Akihito of Japan, now 91, has been diagnosed with supraventricular arrhythmia, a heart rhythm disorder characterized by episodes of abnormally rapid heartbeat, an aide confirmed on Friday. The diagnosis was made during a recent hospital stay at the University of Tokyo Hospital, where the emperor emeritus was undergoing further evaluation for previously identified cardiac issues.
Following the diagnosis, Emperor Akihito was discharged the same day after receiving a new oral medication intended to alleviate the strain on his heart. This new treatment is being administered in conjunction with therapy he had already begun in May, when he was diagnosed with asymptomatic myocardial ischemia—a condition where parts of the heart muscle receive insufficient blood flow, despite the absence of overt symptoms.
Although the emperor emeritus is not experiencing significant side effects from the new medication, physicians have advised caution. To avoid exacerbating his condition, he will refrain from physically demanding activities, particularly those that put stress on the cardiovascular system, such as stair climbing. His walking routine will also be scaled back in both distance and duration.
Accompanied by his wife, Empress Emerita Michiko, 90, the former emperor left the hospital in Tokyo’s Bunkyo Ward at approximately 11:30 a.m. and returned to their residence at the Sento Imperial Palace in Minato Ward. Empress Michiko had reportedly visited her husband every day during his hospitalization, which began earlier this week for dosage monitoring.
Despite the health challenges, the emperor emeritus intends to continue his academic work—particularly his long-standing research on goby fish—at the biological research institute within the Imperial Palace grounds. Whether he will embark on his customary summer retreat remains uncertain and will depend on his recovery in the coming weeks.
This is not the first time Emperor Akihito has faced heart-related issues. In 2022, he was diagnosed with right-sided heart failure due to tricuspid valve insufficiency, a condition in which the valve separating two chambers of the heart does not close properly, causing blood to flow backward. Earlier this year, during a hospital stay in May, further examinations revealed signs of asymptomatic myocardial ischemia. Although initial medications were prescribed to improve blood circulation, they proved insufficient, leading doctors to implement the current additional treatment strategy.
The medical team continues to closely monitor the emperor emeritus’ condition, adjusting treatment as needed to ensure both efficacy and safety given his advanced age. Medical experts note that while supraventricular arrhythmia can be well managed with medication, elderly patients with a history of multiple cardiac concerns must be observed carefully to prevent complications.
Emperor Akihito stepped down from the Chrysanthemum Throne in 2019, becoming the first Japanese monarch to abdicate in over two centuries. His decision to retire was driven in part by health considerations, including his declining physical stamina. He had previously undergone heart surgery in 2012 and has dealt with prostate cancer treatment in the past.
Public sentiment in Japan remains deeply sympathetic toward the former emperor, who is widely respected for his decades of service, humility, and efforts to modernize the role of the monarchy. His abdication marked a historic transition, paving the way for his son, Emperor Naruhito, to assume the throne.
As the nation watches closely, hopes are high that the emperor emeritus will continue to recover comfortably under the care of his medical team and the support of the imperial family. The Imperial Household Agency is expected to provide updates as necessary, particularly if plans for public appearances or travel are affected by his health.
