What is the difference between Wolff-Parkinson-White (WPW) syndrome, Atrioventricular Reentrant Tachycardia (AVRT) and Atrioventricular Nodal Reentrant Tachycardia (AVNRT)?

From the Guidelines

Wolf-Parkinson-White (WPW) syndrome is a congenital condition that predisposes patients to tachyarrhythmias, particularly Atrioventricular Reentrant Tachycardia (AVRT), and requires distinct management approaches compared to Atrioventricular Nodal Reentrant Tachycardia (AVNRT) and Atrioventricular Reentrant Tachycardia (AVRT). WPW syndrome is characterized by an accessory electrical pathway (bundle of Kent) between the atria and ventricles, bypassing the normal AV node, creating a pre-excitation pattern on ECG with a short PR interval and delta wave 1. The key differences between WPW, AVRT, and AVNRT are:

• WPW is an anatomical condition that predisposes to AVRT
• AVRT is a reentrant tachycardia that uses both the normal conduction system and an accessory pathway, creating a circuit
• AVNRT involves a reentrant circuit entirely within the AV node using fast and slow pathways, with no accessory pathway involvement Treatment approaches differ:
• WPW may require catheter ablation of the accessory pathway
• Acute AVRT episodes can be treated with vagal maneuvers, adenosine, or beta-blockers
• AVNRT responds to similar acute treatments but may require ablation of the slow pathway for definitive management In patients with WPW syndrome, the risk of sudden cardiac death (SCD) is increased, particularly in those with short anterograde bypass tract refractory periods (<250 ms) and multiple accessory pathways 1. Catheter ablation of the bypass tract is recommended for most symptomatic patients with WPW, particularly those who have had documented AF or syncope, or those with a short bypass tract refractory period 1. Additionally, patients with WPW in whom AF occurs with a rapid ventricular response associated with hemodynamic instability should be cardioverted immediately due to the high risk of developing ventricular fibrillation 1. Intravenous procainamide may be given to convert the atrial mechanism to sinus rhythm in clinically stable patients with pre-excited tachycardia, while avoiding agents that increase the refractoriness of the AV node, such as digoxin, diltiazem, or verapamil 1. The management of WPW syndrome, AVRT, and AVNRT requires a thorough understanding of the underlying anatomy and physiology, as well as the potential risks and benefits of different treatment approaches 1.

From the Research

Wolf Parkinson White Syndrome vs Avert vs ARVT

• Wolf Parkinson White (WPW) syndrome is a disorder characterized by the presence of an accessory pathway that predisposes patients to tachyarrhythmias and sudden death 2.
• Atrioventricular reentrant tachycardia (AVRT) is the most common arrhythmia in patients with WPW syndrome, accounting for 95% of re-entrant tachycardias 2.
• Atrial fibrillation (AF) is a potentially life-threatening arrhythmia that can occur in patients with WPW syndrome, with an estimated incidence of 10-32% 2, 3.
• The accessory pathway in WPW syndrome can participate in various tachyarrhythmias, including AF, and can have life-threatening consequences by precipitating ventricular fibrillation in patients with rapid conduction 3.
• The pathogenesis of AF in WPW syndrome is related to the presence and functional properties of the accessory pathway, and can be triggered by spontaneous degeneration of atrioventricular reentrant tachycardia or hemodynamic changes during tachycardia 3.
• Treatment options for AF in WPW syndrome include catheter ablation of the accessory pathway, which can eliminate the arrhythmia in more than 90% of patients 3.
• AVRT is a type of supraventricular tachycardia that involves the accessory pathway, and can be treated with catheter ablation or medication 2, 4.
• The term "Avert" is not a commonly used medical term in the context of WPW syndrome or arrhythmias, and it is possible that it may be a typo or a misunderstanding.
• ARVT is not a recognized medical term, and it is possible that it may be a typo or a misunderstanding of AVRT.

Comparison of WPW Syndrome and AVRT

• Both WPW syndrome and AVRT involve the accessory pathway and can cause tachyarrhythmias 2, 4.
• WPW syndrome is a disorder that predisposes patients to tachyarrhythmias and sudden death, while AVRT is a type of supraventricular tachycardia that involves the accessory pathway 2, 4.
• The treatment options for WPW syndrome and AVRT include catheter ablation of the accessory pathway, which can eliminate the arrhythmia in more than 90% of patients 3.

Clinical Presentation and Treatment

• Patients with WPW syndrome and AF can present with symptoms such as syncope, tachycardia, and hypotension 5.
• The electrocardiogram (ECG) can show a fast irregular rhythm with wide polymorphic QRS tachycardia, diagnostic of AF and WPW syndrome 5.
• Treatment options for AF in WPW syndrome include catheter ablation of the accessory pathway, which can eliminate the arrhythmia in more than 90% of patients 3.
• Elective cardioversion can also be used to restore sinus rhythm in patients with AF and WPW syndrome 5.