Atrial flutter is similar to atrial fibrillation (Afib), but atrial flutter has a more steady – if faster than normal – pattern. Both are irregular heart rhythms (arrhythmias) caused by an electrical problem in the heart.
A normal heartbeat begins as a single electrical impulse that comes from the sinoatrial (SA) node, a small area located in your heart’s right atrium (one of the two upper chambers of the heart). The impulse sends out an electrical pulse that causes the atria (the two upper chambers of the heart) to squeeze and move blood into the lower ventricles. The current travels down the electrical bridge between the upper and lower chambers of the heart, called the atrioventricular (AV) node. This causes the ventricles to squeeze and release in a steady, rhythmic sequence. As the chambers squeeze and release, they draw blood into the heart and push it back out to the rest of the body. This is what causes the pulse we feel on our wrist or neck.
With atrial flutter, the electrical signal stays in a cycle within the right atrium. It moves in an organized circular motion, or “circuit,” causing the atria to beat faster than the ventricles of your heart.
In Afib, the heart beats fast and in no regular pattern or rhythm. With atrial flutter, the heart beats fast, but in a regular pattern. The fast, but regular pattern of atrial flutter is what makes it special. Atrial flutter makes a very distinct “sawtooth” pattern on an electrocardiogram (ECG), a test used to diagnose abnormal heart rhythms.
People with atrial flutter usually continue to have a steady heartbeat, even though it’s faster than normal (tachycardia). Without treatment, atrial flutter can cause Afib, the most common type of abnormal heart rhythm.