Atrial Flutter

Rapid, regular tachycardia presenting classically with 2 to 1 block in the AV node and ventricular heart rate of 150 beats/min; ECG shows "sawtooth" pattern of atrial activity (rate 300 beats/min)

Stroke risk should be considered equivalent to that with atrial fibrillation

Catheter ablation is highly successful and is considered the definitive treatment for typical atrial flutter

Less common than atrial fibrillation

May occur in patients with structurally normal hearts but is more commonly seen in patients with

• Chronic obstructive pulmonary disease (COPD)

• Valvular or structural heart disease

• Atrial septal defect

• Surgically repaired congenital heart disease

Typical presenting symptoms include

• Palpitations

• Fatigue

• Mild dizziness

Symptoms and signs of heart failure (dyspnea, exertional intolerance, edema) due to tachycardia-induced cardiomyopathy may be presenting complaints if arrhythmia is unrecognized for prolonged time

ECG typically demonstrates a "sawtooth" pattern of atrial activity in the inferior leads (II, III, and AVF)

The reentrant circuit generates atrial rates of 250–350 beats/min, usually with transmission of every second, third, or fourth impulse through the AV node to the ventricles

Initially, digoxin, a beta-blocker, or a calcium channel blocker (Table 10–11) is used for rate control; conversion to sinus rhythm may result

If not, ibutilide (1–2 mg) converts atrial flutter to sinus rhythm in ~50–70% of patients within 60–90 min

Electrical cardioversion (25–50 J) is effective in ~90% of patients

Precardioversion anticoagulation is not necessary for atrial flutter of < 48 h duration except in the setting of mitral valve disease

Anticoagulation should be continued for at least 4 weeks after electrical or chemical cardioversion and longer in patients with risk factors for thromboembolism

If atrial flutter is recurrent, consider radiofrequency catheter ablation of the reentrant circuit