Led by the Centre for Heart Rhythm Disorders at the University of Adelaide and the South Australian Health and Medical Research Institute (SAHMRI) the study looked at 355 patients with atrial fibrillation a heart rhythm irregularity also known as heart flutter which can lead to stroke heart failure and other serious health conditions. As well as atrial fibrillation all patients also had a body mass index of 27 or over. To put this into context those with a BMI of 25 to 29.9 are classified as overweight and those with a BMI of 30 or higher are considered obese. The participants were