Atrial fibrillation constitutes a major public health problem due to increased risk of stroke and premature death. Norway is facing major demographic changes with increasing number of elderly population, which in turn increases its prevalence and incidence. Thus, there is a need of studying risk factors and consequences for prevention and treatment. We want to investigate this topic in sections: investigate echocardiographic measure with emphasis on diastolic dysfunction as a predictor of atrial fibrillation, atrial fibrillation as a predictor of stroke in relation to CHA2DS2-VASc score, and atrial fibrillation as a predictor of cognitive function in people who have not had a stroke. The investigation will be done based on Tromsø Study 4 and 5 where echocardiographic measurements and cognitive tests were performed respectively. Th eproject is a PhD project for Sweta Tiwari.