An inquest has heard that actor Terence Beesley, who had appeared in TV dramas including Victoria and War And Peace, was found in a car in his garage in Somerset on 30 November.
The coroner said he had heard no evidence “to indicate why Mr Beesley took the act that he did”.
Ms Jensen, 48, who had been in touch with her 60-year-old husband by text and email on the day he died, found him when she arrived home and called the emergency services.
Paramedics tried to revive Mr Beesley at the property in Camerton, near Bath, but he was pronounced dead at the scene at 6.03pm.
In a statement read to Avon Coroner’s Court, Ms Jensen said she had been “extremely shocked” by what had happened and would “never forget it”.
“Terry and I had been together for 18 years but I had no idea he was capable of what he did,” she added.
The couple met in 1999 while working on a production of King Lear.
They had a child together two years after marrying in 2007 and lived in London and Los Angeles before moving to Somerset.
Ms Jensen, who played Christina in the US show Ugly Betty, described her husband as outgoing, saying he had many friends.
He played Derek Branning in EastEnders, as well as appearing in Casualty and The Bill.
His GP, Dr Sam Robinson, said he had “no past medical history of any mental health issues”.
Coroner Peter Harrowing concluded that Mr Beesley’s death had been as a result of suicide, with the medical cause of death carbon monoxide toxicity.
“There is no evidence that I have heard to indicate why Mr Beesley took the act that he did but in any event it is not my function to answer the question why Mr Beesley might have taken that act,” Mr Harrowing said.
“Mr Beesley knew that his wife and young child were not at the house and he would not be disturbed… I am satisfied beyond reasonable doubt that Mr Beesley made a deliberate act.”
:: Anyone feeling emotionally distressed or suicidal can call Samaritans for help on 116 123, or email email@example.com in the UK.