Scientists have developed a smartphone application that can help in screening for atrial fibrillation -the most common heart rhythm disorder.The disorder leads to an irregular, often rapid heart rate that commonly causes poor blood flow.It is also behind 20-30 per cent of all strokes and raises the risk of premature death, but outlook improves dramatically with oral anticoagulation therapy.The novel app measures the heart rhythm using inputs of symptoms such as heart palpitations, shortness of breath or fatigue.It is to be used by holding the left index finger in front of the smartphone camera for one minute.The app also automatically generates a report, along with a copy of the rhythm traces as well as an interpretation, the researchers said."Most people have a smartphone with a camera which is all they need to detect atrial fibrillation. This is a low-cost way to screen thousands of people for a condition which is becoming more prevalent and can have serious consequences unless treated," said principal investigator Pieter Vandervoort, Professor at the University of Hasselt, Belgium.In the study, the participants were instructed to use their own smartphone to measure their heart rhythm twice a day for one week.The average age of the screened population was 50 years and 58 per cent were male.A total of 9,889 (80 per cent) participants had regular (sinus) rhythm, 136 (1.1 per cent) had atrial fibrillation, 2,111 (17 per cent) had other irregular rhythms, and 191 (2 per cent) had measurements of insufficient quality for analysis."This technology has real potential to find people with previously unknown atrial fibrillation so they can be treated," Vandervoort noted.The results were presented at the ESC Congress 2018, the annual conference of the European Society of Cardiology in Munich.