Atrial fibrillation is a kind of irregular heart rhythm.
People with atrial fibrillation sometimes develop blood clots in their hearts. This may lead to stroke if pieces of the clot break off and travel from the heart to the brain. Nevertheless, doctors are sometimes reluctant to prescribe warfarin and patients may be reluctant to take the drug, partly because taking warfarin can lead to bleeding in the gastrointestinal tract or bleeding into the brain. They wanted to find out how often patients with atrial fibrillation use warfarin and what factors were associated with a person using this medicine or not using it. Nonvalvular atrial fibrillation is the most common type of this heart rhythm problem.