Although no one knows for sure what triggers or causes atrial flutter, it is likely from the risk factors listed in the next section. In individuals with these risk factors, some injury probably occurs to alter the healthy electrical pacemaker in the heart atrium that allows a reentry loop for electrical signals to follow. The sinus node sends out an electric signal, but travels along the continuous loop in atrial flutter causing the atria of the heart to contract rapidly, usually with the atria contracting faster than the ventricles although some individuals with the heart disease can have about a 1:1 conduction that results in a heartbeat of about 250 – 300 bpm.

There are many risk factors for this type of flutter. The following is a list of some of the more common risk factors:
High blood pressure
Obesity
Diabetes
Heart failure
Ischemic heart disease and/or a previous heart attack
Serious acute illnesses
Heavy alcohol intake and/or binge drinking
Advanced age
Hyperthyroidism
Chronic lung disease
Recent surgery
Congenital heart disease