Atrial flutter

Hindricks, 2021January, 2014January, 2019Page, 2016

Atrial flutter often presents with 2:1 atrioventricular (AV) block and a regular ventricular rate of 150 beats per minute. It occurs in many of the same situations as atrial fibrillation but is less common. Atrial flutter is often misdiagnosed as supraventricular tachycardia, but a ventricular rate of 150 beats per minute with narrow QRS complexes should always alert the clinician to the likelihood of atrial flutter.

A greater degree of AV block may be present, giving a ventricular rate of 100 (3:1 block) or 75 (4:1 block). Rarely, conduction can be 1:1, giving a ventricular rate of 300. In some patients, conduction may be variable, producing irregular ventricular rates.

Atrial flutter commonly reverts with a low-energy direct current (DC) shock or with overdrive pacing but it is often insensitive to antiarrhythmic drug therapy (eg adenosine will not revert atrial flutter, but it may expose flutter waves). Therefore, electrical cardioversion is often performed earlier in patients with atrial flutter than in patients with atrial fibrillation. Apart from this, the management of atrial flutter and atrial fibrillation is generally the same regarding drug therapy, choice of rhythm versus rate control, and prevention of thromboembolic complications.

If atrial flutter is recurrent, consider catheter ablation; seek specialist advice.