This is the heroic moment a quick-thinking nurse saved a heart attack victim when he collapsed in a hospital waiting room.

Footage shows the man, Ken Nguyen, wearing a white shirt, suddenly falling to the floor in the lobby of Nam Quang Tri Eye Hospital in Vietnam on the morning of October 14.

Stunned patients panicked, but a woman in a pink-and-white striped top quickly alerted the nurses at the reception desk.

Calm-headed Nurse Le Thi Thu Ha immediately activated the hospital's emergency alarm and coordinated with the medical staff in the Examination Department to provide initial emergency care.

Using cardiopulmonary resuscitation (CPR), the team worked swiftly to stabilise Ken. He was quickly transferred to the intensive care unit at a general hospital, where doctors continued treatment.

Ken's friend told local media had come for a medical examination and had a history of two previous transient strokes.

The hospital management praised Nurse Ha for her prompt and professional response, saying her quick actions had directly saved a life. She was also formally recognised and rewarded by the medical centre for her heroism.