Catherine Bonner, 55, died and her partner, Jim McColl, 55, was badly hurt in the crash in Fairlie in 2013.
A Fatal Accident Inquiry heard from a doctor who said driver George Marshall had an underlying medical condition.
A charge of death by dangerous driving was dropped by the Crown after it had looked into his medical background.
The two-storey house on the A78 coast road was struck at its corner, demolishing the gable end and exposing an upstairs bedroom, the hearing at Kilmarnock Sheriff Court was told.
The lorry had been heading south when it crossed into the opposite carriageway without taking the bend and hit Ms Bonner's home.
Dr Peter Bloomfield, 64, a retired consultant cardiologist examined Mr Marshall, 53, after the crash.
He described how he had rubbed on Mr Marshall's left carotid sinus at the base of his carotid artery in his neck, and his heart had stopped for six seconds.
The doctor said Mr Marshall's blood pressure recorded a "significant fall" after this.
He concluded that the driver had a condition known as carotid sinus hypersensitivity and had suffered an episode "following an explosive fit of coughing", stopping blood getting to his heart.
Dr Bloomfield explained: "That can result in someone passing out, which is what Mr Marshall described.
"In my opinion, the episode of coughing was clearly linked to loss of control of the vehicle."
Mr Marshall said he had not experienced anything like it before and was shocked that his truck had gone into the building.
William McCrindle, 77, who was driving two cars behind the lorry and was first at the scene of the crash said the scene was "almost like a disaster movie".
He said: "There was a colossal bang and bricks were flying everywhere.
"The truck was embedded so far in I thought the driver would be killed.
"I waited long enough to see the driver being helped out of the cab and he didn't seem to be seriously injured."
It had earlier been reported that Ms Bonner and Mr McColl had been watching TV at the time of the accident.
They were both taken to Inverclyde Royal Hospital where Ms Bonner died of her injuries.
The court heard that Mr McColl would not be giving evidence.
The inquiry before Sheriff Iona McDonald continues.
The driver of a lorry which crashed into a house killing a woman had blacked out with an "explosive coughing fit", a court has heard.