The CEO is a stalwart of the US banking sector, often outspoken and willing to defend the business. Its co-COOs are running the business while Dimon recovers.

JP Morgan’s chief executive Jamie Dimon is recovering from emergency heart surgery performed yesterday. Two of his deputies are taking over while he recovers.

Dimon, 63, suffered a tear in his heart's main artery, which was detected early and treated successfully, the bank said in a memo that was publicly issued and shown to Family Wealth Report.

The CEO is "awake, alert and recovering well," the memo said.

The bank's co-presidents and co-chief operating officers, Daniel Pinto and Gordon Smith, sent the message to all employees, and are running JP Morgan as Dimon recovers.

A prominent figure in US banking, Dimon has been at the helm for more than 10 years, a period including the global financial crash. He is outspoken in defense of the banking sector and free market capitalism, contrasting perhaps with what can appear to be a muted stance by some of his peers.

The CEO has wrestled with health issues before, recovering from cancer treatment in 2014.