Experts from the University of Sydney said the cheap device, known as the AliveCor Heart Monitor for iPhone (iECG), was highly effective and accurate in screening patients with undiagnosed atrial fibrillation (AF).
The study was revealed Friday at the Australia and New Zealand Cardiac Society conference in Queensland, Xinhua reported.
The device was invented by an Australian scientist and a US cardiologist.
Ben Freedman, professor at the University of Sydney, and his colleagues tested the device on randomly selected people aged 65 or older at 10 pharmacies in Sydney.
He said the device was an exciting breakthrough and can be operated without special skills.
"Atrial Fibrillation is the most common heart rhythm problem and is responsible for almost one third of all strokes," he said.
"AF increases with age, affecting more than 15 percent of people aged 85 years and over."
Freedman said people with atrial fibrillation face up to a five-fold increased risk of stroke, and tend to have more severe and life-threatening strokes.
He said the research shows around 50,000 Australians aged over 65 have AF, but do not know it.
"There are currently a large number of people with unknown AF who are at high risk of stroke, but who are not on any medication," he said.
"The iECG allows us to screen patients for atrial fibrillation in minutes, and treat people early."