- The kent bundle is the most common bypass tract in the heart
- WPW affects about 0.2% of the general population, and about 70% of them have no evidence of cardiac disease
- About 60-70% of all WPW cases are men
- WPW is most commonly recognized and diagnosed in children and young adults after they present to the ER with an arrhythmic event.
- Very fast rate, your SVT, or A-fib/flutter patients may have much faster rates than normal(well normal for an accelerated rhythm).
- Delta wave
- Shortened PR-Interval
- Fast broad and irregular rhythm that isn't torsades
This grossly irregular, rapid right bundle-branch block tachycardia represented preexcited atrial fibrillation (AF) with anterograde conduction over a left posterolateral accessory pathway, leading to irregularly irregular preexcited ventricular complexes with varying degrees of preexcitation. The shortest RR interval during preexcited AF was 160 ms, indicating a short anterograde refractory period of the accessory pathway and an increased risk for the development of ventricular fibrillation and sudden death.
The differential diagnosis of preexcited AF includes ventricular tachycardia and atrial fibrillation with aberrancy. The presence of an apparent fusion and capture beat could lead one to the diagnosis of ventricular tachycardia, because these findings are considered diagnostic for ventricular tachycardia. Morphologically speaking, the tachycardia is ventricular in origin. Nevertheless, the marked cycle-length variation of more than 100% strongly argues against ventricular tachycardia and instead favors preexcited AF as the underlying arrhythmia mechanism. The right superior axis deviation and the fact that longer RR intervals lead to more fully preexcited QRS complexes compared with shorter RR cycles (the concertina phenomenon) virtually exclude AF with solely aberrant conduction.
Preexcited atrial fibrillation with rapid ventricular response reveals a typical electrocardiographic pattern that is often diagnostic at first glance. Because of its characteristic ECG features (fast, broad, and irregular), this tachyarrhythmia has been named FBI tachycardia. This potentially life-threatening clinical condition is obviously a case for the emergency rather than the secret service.
ABSTRACTThe safest and most effective treatment for any unstable tachycardia with a pulse is synchronized cardioversion. As always, follow your protocols no matter what you read here. Here are a couple more links from The Prehospital 12-Lead Blog. Link 1 & Link 2.
Wolff–Parkinson–White (WPW) syndrome with atrial fibrillation (AF) is a potentially life-threaten- ing problem requiring rapid conversion to sinus rhythm. The most recent American Heart Associa- tion guidelines for the treatment of patients with WPW, published in conjunction with the 2000 Advanced Cardiac Life Support (ACLS) guidelines, suggests that intravenous amiodarone is a first- line therapy for AF–WPW; however the evidence suggests this is a potentially dangerous myth.
*All images, including ECGs, are from various web sites found with Google. They are only to be used for educational purposes.