Premature beats originating from the atrioventricular accessory pathway

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Ventricular pre-excitation, commonly known as Wolff-Parkinson-White (WPW) syndrome, involves an accessory pathway for electrical conduction.
• Patients may exhibit varying degrees of pre-excitation, impacting cardiac rhythm diagnosis.

Purpose of the Study:

• To report a unique case of WPW syndrome with alternating manifest WPW complexes and normal beats.
• To describe premature beats in this patient that mimicked other supraventricular tachycardias.

Main Methods:

• Case report analysis of a 34-year-old male patient.
• Electrocardiographic (ECG) evaluation under sinus rhythm.

Main Results:

• The patient displayed alternating fully manifest WPW complexes and normal sinus beats.
• Observed premature beats, unrelated to P waves, showed WPW morphology.
• These premature beats were at risk for misdiagnosis as accelerated idioventricular rhythm or junctional rhythm with left bundle branch block (LBBB).

Conclusions:

• The presentation of alternating WPW complexes and specific premature beats poses diagnostic challenges.
• Awareness of this pattern is crucial to avoid misdiagnosis of other cardiac arrhythmias.