Atrial flutter management and atrial fibrillation features
THE CONTEXT
Atrial flutter can be managed by controlling the ventricular rate or restoring rhythm. The target passage also describes mechanisms and electrocardiographic features of atrial fibrillation.
Rate and rhythm control in atrial flutter
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Rate control uses atrioventricular (AV) node-blocking drugs such as β-blockers, verapamil or digoxin to control the ventricular rate.
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Rhythm control is preferable in most cases and can be achieved by direct current (DC) cardioversion or catheter ablation.
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DC cardioversion has a high recurrence rate, even when β-blockers or amiodarone are used afterwards.
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Class Ic anti-arrhythmic drugs such as flecainide are contraindicated because they can cause paradoxical extreme tachycardia and haemodynamic compromise.
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Catheter ablation offers a greater than 90% chance of permanent cure and is the treatment of choice for patients with persistent symptoms.
Anticoagulation
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Anticoagulant management in atrial flutter, including management around cardioversion, is identical to that in atrial fibrillation.
Atrial fibrillation: mechanism and ECG
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Ectopic beats, often arising from the pulmonary veins, trigger atrial fibrillation. Multiple interacting re-entry circuits within the atria maintain it.
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The electrocardiogram (ECG) shows irregular QRS complexes and no P waves.
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At onset, the ventricular rate is usually fast, between 120 and 160/min.
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In chronic atrial fibrillation, medication and AV nodal fatigue may produce a much slower ventricular rate.