Atrial Fibrillation

Presentation

This is very unusual in pediatric practice. It usually occurs following surgery for complex disease or late repair (or un-operated) of atrial septal defects. It may also occur following an alcoholic binge in those with otherwise normal hearts.

It results in a 30% decrease in ventricular filling due to loss of atrial contraction and in those with borderline cardiac function can result in severely compromising cardiac output.

Mechanism

This is considered to be a macro re-entrant tachycardia. The anatomical substrate may include the atrial suture line following cardiac surgery.

ECG

This is classically an irregular irregular rhythm. The rate is dependent upon the ability of the AV node to conduct through the His-Purkinje system to the ventricles.

Atrial fibrillation

Management

If the circulation is acutely compromised then DC cardioversion is appropriate. Amioderone, sotalol and flecainide have all been used to convert to sinus rhythm and maintain it. In selected subgroups radiofrequency ablation and arrhythmia surgery may be helpful. When restoration and maintenance of sinus rhythm is not achievable then symptoms may be reduced by controlling the ventricular response. with digoxin, β blockers or calcium antagonists.

Prognosis

Once chronic atrial fibrillation is established it can be very difficult to convert to and maintain sinus rhythm .

This page was last edited 14/2/2004

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