Suspected fatal medical incident during heart operation at Tuen Mun Hospital

A 75-year-old patient reportedly dies after undergoing angioplasty surgery at Tuen Mun Hospital.

Sources say the incident was caused by air embolism, possibly because of defects in devices used during the operation.

That's when air bubbles entere blood vessels, which leads to cardiac arrest.

The case has been reported to the Department of Health for follow-up probes.