Inhomogeneity and complexity in defining fractionated electrograms

Area of Science:

• Cardiac Electrophysiology
• Medical Device Technology

Background:

• Atrial fibrillation (AF) ablation strategies targeting complex fractionated atrial electrograms (CFAEs) have shown limited success.
• Fractionation in atrial electrograms can stem from various pathologic and nonpathologic origins, complicating treatment.
• A lack of standardized definitions hinders accurate identification of abnormal cardiac electrical activity.

Purpose of the Study:

• To systematically review and analyze existing definitions and measurement methods for electrogram fractionation in human atrial electrophysiology.
• To identify the diversity in definitions and parameters used to characterize CFAEs in scientific literature.
• To highlight the need for a uniform approach to defining and measuring fractionation for improved AF treatment.

Main Methods:

• A systematic literature search was conducted using PubMed for studies on human atrial electrophysiologic measurements describing fractionation.
• Articles were screened for novel definitions of fractionation, automated detection programs, and measurement parameters.
• Data on visual definitions, automated detection algorithms, measurement parameters, and continuous electrical activity definitions were extracted.

Main Results:

• The search identified 348 articles, with 24 studies meeting the criteria.
• These 24 studies presented 11 distinct visual definitions for fractionation, 3 automated CFAE detection programs, and 7 new measurement parameters.
• Five different definitions for continuous electrical activity were also found, with electrode properties often poorly described.

Conclusions:

• There is a significant lack of uniformity in definitions and recording methodologies for measuring cardiac atrial electrogram fractionation.
• Varied electrophysiologic causes and the influence of recording device properties impede the identification of true pathologic inhomogeneous conduction.
• Establishing consistent methods for identifying pathologic fractionation, potentially by correlating electrogram morphology with activation patterns, is essential before refining ablation strategies.