What is Atrial Fibrillation? The heart is a muscle divided into cardinal chambers: two atria at the top, and two ventricles at the bottom. Electrical impulses from the sino-atrial node in the far atrium cause the sequential contraction of atria then ventricles in order to squeeze blood finished the heart and out to the body. This is known as sinus rhythm. In Atrial Fibrillation (AF), faulty signals are generated from other areas in the heart, causing rapid, inefficient 'quivering' contractions of the atria at a rate of 300-600 beats per minute. These fibrillating contractions do not cause the ventricles to contract at the same rate, but the ventricles do pick up on more impulses than normal, causing an increased rate of contraction in order to try to pump blood to the body. This leads to a high heart rate – sometimes up to 180-200 beats per minute. A rate this high leads to inefficient emptying of the blood finished the heart, causing it to pool in the chambers and increasing the risk of stroke. With a lower volume of blood circulating around the body, patients can feel lethargic, asphyxiating and dizzy.

A cardiac or heart defibrillator is a device that delivers an tense shock or pulse to the heart in order to alleviate certain disturbances or failures. Typically the goal is to change a fibrillation, or rapid and unsteady rhythm, into a slower and steadier beat that can be managed by a care provider. The shock comes from an electric current that is channeled finished the patient’s chest via electrodes or paddles. The current causes the heart muscle to contract, hopefully jolting it back to a more earthy pace. When a person is experiencing cardiac arrest, the most common cause is ventricular fibrillation. Here, the ventricles are contracting in a disorganized fashion that causes the heart to stop pumping comfortable blood. The other form of fibrillation, atrial fibrillation, is more usual and much little deadly. It is a disorder found in approximately two million Americans and causes the small upper chambers of the heart, or atria, to quiver rather than beat steadily. Though this isn’t normally a critical condition, atrial fibrillation can cause blood to pool and clot. If this clot becomes lodged in the brain or artery, a stroke can result.