Wolf-Parkinson-White syndrome with atrial fibrillation

A 47 year old man with a long history of palpitations and, lately, blackouts.

irregularly irregular, wide complex tachycardia

impulses from the atria are conducted to the ventricles via either

• both the AV node and accessory pathway producing a broad fusion complex
• or just the AV node producing a narrow complex (without a delta wave)
• or just the accessory pathway producing a very broad 'pure' delta wave

people who develop this rhythm and have very short R - R intervals are at higher risk of VF