A City banker died following major heart surgery at a private London hospital after a vital piece of equipment was switched off for 19 hours, an inquest heard.

Robert Entenman, 57, died after an operation to repair a broken valve in his heart at London Bridge Hospital, one of the largest private hospitals in the UK.

Mr Entenman, who was the global head of e-commerce for Uni-Credit Bank, had successfully come through the operation on May 15 last year, but went into respiratory cardiac arrest eight days later when a ventilator pipe became blocked with mucus, Southwark coroner’s court was told.

The inquest heard that the humidifier on the ventilator, which helps prevent the accumulation of mucus in the lungs, had been turned off for 19 hours.