An ultrasound scan carried out on a gorilla's heart could help research into human heart disease.
Paignton Zoo vets were joined by scientists from a Welsh cardiovascular research laboratory for the tests.
The scan and other tests were carried out on Kumbuka, a 15-year-old adult silverback lowland gorilla.
Great apes tend to live longer in zoos, prompting questions about whether their cardiac problems could be linked to a more sedentary lifestyle.
Subtle differences in human and great ape hearts could also help to explain how the human heart may have evolved.
Robert Shave and Eric Stöhr from the Cardiovascular Research Laboratory at Cardiff Metropolitan University took echocardiographic images of Kumbuka's heart.
In addition, they took blood samples to help establish a normal value for gorillas of substances in the blood that can indicate heart problems and they also carried out karyotyping - a genetic test to examine chromosomes in a sample of cells.
The heart health statistics for zoo apes are similar to those of humans and about a third of gorillas that died in US zoos were found to have some form of heart disease.
The British Heart Foundation estimates that the same conditions claim the lives of about one in three men and women in the UK.
One train of thought is that life in a zoo can be too easy for apes, with lots of good food and not enough incentive to take exercise.
In that respect it mimics the sedentary, easy-going modern lifestyle that is linked to cardiac problems in humans.
Ghislaine Sayers, head of veterinary services at the zoo said: "We know that apes in zoos can suffer from heart problems.
"It could just be a genetic problem - something these animals are predisposed to - or it could be down to the fact that as they generally live longer in zoos than in the wild, there is a greater chance of heart disease becoming an issue.
"We had to do a routine health check on Kumbuka, so we arranged to do the ultra-sound at the same time."
Ms Sayers said the results of the tests will go to the Great Ape Heart Project - an international initiative collecting data on ape hearts.
"There are two main aims - to work out what is normal for an ape heart and to help us detect any cardiac problems in our apes early on," she added.
The zoo said Kumbuka, who weighs 180kg (28st), has made a full recovery from the anaesthetic, oblivious to the contribution he is making to medical research.
The results of some of the tests on the gorilla will not be known for several weeks.