Atrial fibrillation, also referred to as AF, is the most common type of cardiac arrhythmia (irregular heart rate or rhythm), and it is the #1 cause of stroke, effecting 3.5 million Americans. AF occurs when electrical signals from the heart’s two upper chambers “fibrillate” or quiver.
During each heartbeat, electrical signals spread from the top of the heart to the bottom. The electrical signals begin in a group of cells called the sinus node or sinoatrial (SA) node, which are located in the right atrium. The signals travel from the SA node through the right and left atria, which cause the blood to pump through the ventricles. The signals then move to a group of cells called the atrioventricular (AV) node, which are located between the atria and ventricles. This signal leaves the AV node and travels to the ventricles, causing them to pump blood to the lungs and rest of the body.
During AF, the electrical signals do not begin in the SA node. They begin in another part of the body and don’t travel normally, causing the atria to fibrillate. These bad signals flood the AV node and cause the ventricles to beat fast. The AV node can’t send the signals to the ventricles fast enough, so as they are beating faster than normal they are not beating in line with the atria. This causes an irregular heartbeat that can cause ventricles to beat 100 to 175 times a minute, which is well beyond the normal 60 to 100 beats a minute.
AF usually causes no symptoms at all. Sometimes they come and go, while at other times they are ongoing and permanent. When symptoms do occur they include:
- Intermittent palpitations
- Trouble breathing
- Chest pain
Treatment for atrial fibrillation can include pacemakers, defibrillators, cardiac resynchronization therapy devices and ablation. At Sinai Hospital we focus on ablation, a catheter-based procedure that delivers electrical signals to the heart tissue to stop abnormal firings of the heart.