Atrial fibrillation is the most common heart beat Oslo - UPI The strongest risk factors for atrial fibrillation in both men and women were a history of palpitations and hypertension, researchers in Norway found. First author Dr. Audhild Nyrnes of the University of Tromso in Norway said hypertension was a well known risk factor for atrial fibrillation, but the the impact of self-reported palpitations had not been previously documented. Participants in the Tromso study were recruited in 1994 to 1995 and from a field that included all inhabitants in the region age 25 and older. After exclusions, 22,815 people ages 25-96 were studied and followed up for a mean time of 11.1 years. Mean age at baseline was 46 years. The study showed atrial fibrillation was recorded in 3 percent of women and 4.2 percent of men during the 11.1 years of follow-up. Age, self-reported palpitations and hypertension were the strongest risk factors for atrial fibrillation, the study found. The study, published in the the European Journal of Preventive Cardiology, found palpitations -- which the investigators described as \"frequent\" in the total study group -- increased the risk of atrial fibrillation in women by 62 percent and in men by 91 percent. \"However, palpitations are in fact mostly harmless; the challenge is to detect those which might signify an underlying condition and future atrial fibrillation,\" Nyrnes said. \"Thus, while palpitations might be reduced by modifying lifestyle factors, such as alcohol consumption and smoking, both of which increase heart rate, it is still unclear if this will reduce the risk of atrial fibrillation.\"