Atrial flutter is a condition in which the atrium beats 250 to 350 times per minute. This causes rapid, regular or irregular heart rhythms similar to atrial fibrillation. Atrial flutter is different from atrial fibrillation because the electrical activity of the atrium is not disorganized; it is just very fast. One can actually see rapid "flutter waves" on the ECG that resemble a sawtooth pattern. Atrial flutter occurs when an abnormal electrical signal gets stuck rapidly circulating around the atrial muscle tissue. Most cases of atrial flutter occur in patients with underlying heart disease, but "lone" atrial flutter can also occur. The treatment of atrial flutter is similar to atrial fibrillation with medications first to slow AV conduction and control the ventricular rate, followed by medications to convert the flutter back to a normal sinus rhythm and prevent its recurrence. Electrical cardioversion is usually required, however, to restore a normal rhythm, after which anti-arrhythmic drugs can be used to maintain a normal sinus rhythm. Atrial flutter is not as common as atrial fibrillation, but fortunately we have learned a tremendous amount about it. Most atrial flutter is curable with Catheter Ablation, a highly successful means of permanently eliminating the flutter circuit. Catheter ablation in involves passing a small wire up from the vein at the top of the leg. The flutter circuit is "mapped" to determine where it is located, and then the wire is used to destroy a small portion of the circuit to prevent recurrence. Comparative studies have shown that the success rate of catheter ablation is much better than medical therapy for atrial flutter, and ablation is now considered the best treatment for this arrhythmia.
Patients who have atrial flutter may be at increased risk of developing a blood clot in the atrial chambers, similar to patients with atrial fibrillation. This can lead to a stroke. Strokes due to atrial flutter and fibrillation are very serious, and most people who have atrial flutter must take some kind of blood thinner to decrease the risk of clots formation within the atria, unless the flutter can be permanently eliminated with catheter ablation.