Atrial flutter (AFL) is a type of abnormal heart rate, or arrhythmia. It occurs when the upper chambers of your heart beat too fast. When the chambers in the top of your heart (atria) beat faster than the bottom ones (ventricles), it causes your heart rhythm to be out of sync.

Typically, a person with AFL doesn’t feel the fluttering of their heart. Symptoms often manifest in other ways. Some of them include:

fast heart rate
shortness of breath
feeling lightheaded or faint
pressure or tightness in the chest
dizziness or lightheadedness
heart palpitations
trouble doing everyday activities because of fatigue

Stress also raises your heart rate, and can exacerbate symptoms of AFL. These symptoms of AFL are common in many other conditions. Having one or more of these symptoms is not always a sign of AFL. Symptoms often last for days, or even weeks, at a time.