What are the complications of atrial fibrillation?

Heart FailureIf the heart is unable to pump an adequate amount of blood to the body, as in some people with AF, the body begins to compensate by retaining fluid. This can lead to a condition called heart failure. Heart failure results in the accumulation of fluid in the lower legs (edema) and the lungs (pulmonary edema). Pulmonary edema makes breathing more difficult and reduces the ability of the lung to add oxygen to and remove carbon dioxide from the blood. The levels of oxygen in the blood can drop, and the levels of carbon dioxide in the blood can rise, a complication called respiratory failure. This is a life-threatening complication.
StrokeQuivering of the atria in AF cause blood inside the atria to stagnate. Stagnant blood tends to form blood clots along the walls of the atria. Sometimes, these blood clots dislodge, pass through the ventricles, and lodge in the brain, lungs, and other parts of the body. This process is called embolization. One common complication of AF is a blood clot that travels to the brain and causes the sudden onset of one-sided paralysis of the extremities and/or the facial muscles (an embolic stroke). A blood clot that travels to the lungs can cause injury to the lung tissues (pulmonary infarction), and symptoms of chest pain and shortness of breath. When blood clots travel to the body's extremities, cold hands, feet, or legs may occur suddenly because of the lack of blood.