Atrial fibrillation, accessory pathway and risk of sudden death

Patient

Young man 17 years of age with no particular prior history having presented a recovered sudden death during a football game (electric shock delivered with a semi-automatic external defibrillator); patient referred to the department; an accessory pathway pattern is discovered and an electrophysiological study is performed in order to measure the anterograde refractory periods of the accessory pathway;

Trace

An electrophysiological study was performed to measure the anterograde refractory periods of the accessory pathway; rapid atrial pacing and injection of isoproterenol to promote conduction in the accessory pathway; typical tracing of atrial fibrillation due to accessory pathway with characteristic accordion-like pattern; presence of very short RR cycles;

Trace

Extremely short RR cycles; in the second part of the tracing, the rhythm degenerates into ventricular fibrillation (disorganized activity); loss of consciousness of the patient; an electric shock is thus necessary to restore an effective sinus rhythm;

Exergue

The presence of atrial fibrillation rapidly conducted by the accessory pathway constitutes the determining prognostic element of these patients. A short anterograde refractory period exposes the patient to the risk of sudden death and is a formal indication for ablation.