Atrial flutter

Atrial flutter (AFL) is an ectopic tachycardia originating in the atria, caused by reentry of the impulse within the atria, and can convert to atrial fibrillation. Also known as macroreentrant atrial tachycardia, it is a rapid and regular atrial ectopic rhythm with a frequency between 250 and 350 beats per minute, with varying atrioventricular conduction ratios from 2:1 to 4:1, ventricular rate of 125-175 beats/min, QRS not widened, and the ventricular rate may slow after drug therapy. Electrophysiological studies have shown that atrial flutter is caused by reentry and can be divided into two types: cavotricuspid isthmus-dependent atrial flutter and non-cavotricuspid isthmus-dependent atrial flutter.