Atrial fibrillation is a disorder in which the beating of the heart's upper chambers, or atria, develops a rapid, chaotic rhythm that does not coordinate with that of the lower chambers, or ventricles. It is important to treat the condition, as the complications of atrial fibrillation can be serious. Since the atria have an abnormal rhythm, or dysrhythmia, they may fail to empty properly and the blood remaining inside may clot. A clot can travel in the circulation until it reaches and obstructs a blood vessel in the brain, causing a stroke. The unsynchronized heart rhythm also lowers the efficiency with which the heart pumps blood around the body and, if the condition progresses, heart failure may result.
Normally, the heart's beat is triggered by an area of tissue, called the SA node, which acts as a pacemaker. An electrical impulse from the SA node spreads to involve the atria, causing contraction, and, after a slight delay, the impulse reaches the ventricles, causing them to contract and squeeze blood out of the heart. The impulses fire off at regular intervals, setting up what is called a normal sinus rhythm. In atrial fibrillation, many abnormal impulses fire off at random and override those of the SA node, causing heart quivering. Palpitations and chest pain may be experienced, and, as the heart is less efficient, a reduced blood supply to the rest of the body results in symptoms such as breathlessness and dizziness.
One of the major complications of atrial fibrillation, a stroke, results from clots forming inside the atria. Incomplete emptying of the atria leads to blood stagnating inside the chambers, increasing the risk of clots forming. The erratic contractions of the atria cause a turbulent flow of blood, which also makes clot development more likely. Treatment can help prevent the complications of atrial fibrillation. The range of options includes drugs, surgery and other procedures, together with regular doses of anticoagulant medication to reduce the chance of clot formation.
A stroke occurs when a clot is carried to the brain and blocks the blood supply to an area of brain tissue, resulting in symptoms such as paralysis on one side of the body. The complications of atrial fibrillation may also involve clots lodging in blood vessels in the lungs, causing breathing difficulties and chest pain, or in the limbs, hands and feet, causing sudden coldness. Treatment may involve the use of drugs to break up the clot and anticoagulant medication to prevent further clotting.
Heart failure is another of the complications of atrial fibrillation, and fluid may build up in the lungs and legs as the heart becomes less effective. Swollen ankles and legs, and breathlessness may be experienced. Heart failure is treated using medication, together with lifestyle changes such as giving up smoking, eating more healthily and taking regular exercise.