Title : Irregular wide complex tachycardia in a young man
Introduction: Wolf-Parkinson-White (WPW) syndrome constitutes an uncommon cause associated with atrial fibrillation (AF). Only a few reports are documenting AF presentation as an irregular wide complex tachycardia in patients with WPW. This kind of tachycardia may be the first presentation of this underlying conduction abnormality in young patients. In this case study, we describe a case of a young patient with the WPW syndrome presenting with an irregular wide complex tachycardia of unknown etiology.
Case presentation: A 22-year-old man presented to the emergency department with an episode of tachycardia, and hypotension. A 12-lead electrocardiogram showed rapid, irregular, wide complex tachycardia, a very rapid heart rate (up to 220 bpm in places)
Fast AF could not be seen, but instead, there was a subtle beat-to-beat variation in the QRS width which was more typical of WPW associated with AF. AF was suggested by the completely irregular ventricular actions.
Elective cardioversion restored sinus rhythm. Subsequent electrocardiogram in sinus rhythm showed features of left-sided WPW accessory pathway, short PR interval, and delta waves, positive in V1, and negative in aVL. Successful radiofrequency ablation of the accessory pathway completely prevented further inducible atrial fibrillation.
Discussion: The second clinically relevant arrhythmia encountered in these patients is atrial fibrillation with very rapid ventricular rates due to almost exclusive A-V conduction by way of the accessory pathway. The usual rate-slowing drugs used in AF are not effective, and digoxin and the nondihydropyridine calcium channel blockers (e.g., verapamil and diltiazem) are contraindicated because they may increase the ventricular rate and cause ventricular fibrillation. AF with underlying WPW syndrome presenting with irregular wide complex tachycardia can cause sudden cardiac death by precipitating ventricular fibrillation. Treatment of choice for WPW syndrome is radiofrequency ablation.
Audience take away:
• Atrial fibrillation with underlying WPW presents with irregular wide complex tachycardia, and can cause sudden cardiac death by precipitating ventricular fibrillation if remain undiagnosed and properly treated.
• Irregular wide complex tachycardia may be the first presentation of this underlying conduction abnormality in young patients.
• Treatment of choice for WPW syndrome is radiofrequency ablation.