 Dr. Ranjan Shetty, Interventional Cardiologist in Manipal Hospital, Bangalore. Hatal fibrillation is the most common cardiac arrhythmia. What happens in this condition is the upper chamber, heart as the upper chamber and the lower chamber, the upper chamber actually starts vibrating and not technically beating and the lower chamber is the one which continues to beat. This produces lots of problems. It's a disease of elderly, above 60% of the population has this disease and about 85-10% of the population has this disease. This is not just change of rhythm which we are talking about here. The claws can form in this and this is one of the very important ways cause for stroke in elderly and stroke you know is very disabling and does affect the quality of life of this elderly. To prevent stroke in atrial fibrillation there is some therapies available. One option is drug like warfarin or some of the newer drugs. These are strong blood thinners. They would prevent stroke when they can appropriately but there is also risk of lot of bleeding which can occur, which can be stomach or which can be skin or whenever there is a need for surgery these drugs need to be thought.