Extra AV nodal Wenckebach periodicity

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Electrophysiology

Background:

• Wenckebach periodicity is a type of atrioventricular (AV) block.
• Extra AV nodal Wenckebach periodicity involves block occurring outside the typical AV node.
• This condition can manifest in various locations within the heart's conduction system.

Purpose of the Study:

• To diagnose and characterize extra AV nodal Wenckebach periodicity.
• To differentiate its various forms and locations.
• To discuss the clinical significance of this conduction abnormality.

Main Methods:

• Diagnosis of extra AV nodal Wenckebach periodicity in seven patients.
• Analysis of electrocardiogram (ECG) findings to determine block location.
• Classification based on the site of conduction delay (sinoatrial junction, atria, AV junction, ventricle, bundle branches, reentry pathway).

Main Results:

• The most frequent presentation was extra AV nodal exit block.
• Underlying block locations varied: sinoatrial junction/atria (2 patients), AV junction (1 patient), ventricle (1 patient).
• Wenckebach periodicity in bundle branches or reentry pathways occurred in one patient each, with diagnosis aided by visible ECG conduction delay.

Conclusions:

• Extra AV nodal Wenckebach periodicity presents with diverse underlying block locations.
• Diagnosis in exit block relies on specific P-P or R-R interval patterns due to unobserved conduction delay.
• The clinical significance of these varied forms of Wenckebach periodicity warrants further discussion.