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Simultaneous Endo-Epicardial Mapping of the Human Right Atrium: Unraveling Atrial Excitation
Rohit K Kharbanda1,2, Paul Knops1, Lisette J M E van der Does1
1Department of Cardiology Erasmus Medical Center Rotterdam The Netherlands.
Insights
Endo-epicardial asynchrony and conduction block in the atria are present during sinus rhythm. These conduction abnormalities are more severe in patients with cardiovascular risk factors or persistent atrial fibrillation.
Area of Science:
- Electrophysiology
- Cardiac Anatomy
- Atrial Fibrillation Pathophysiology
Background:
- The role of endo-epicardial asynchrony (EEA) and atrial conduction block (CB) in atrial fibrillation (AF) pathophysiology during sinus rhythm remains unclear.
- Understanding these electrical phenomena is crucial for developing targeted therapies for AF.
Purpose of the Study:
- To investigate the 3-dimensional activation patterns of the human right atrium (RA) during sinus rhythm.
- To analyze the prevalence and characteristics of endo-epicardial asynchrony and conduction block in the RA.
Main Methods:
- Simultaneous endo-epicardial mapping of the inferior, middle, and superior RA in 80 patients.
- Definition of conduction block (CB) as delays ≥12 ms, EEA as activation differences ≥15 ms, and transmural CB at similar sites.
- Statistical analysis to correlate conduction abnormalities with patient history and cardiovascular risk factors.
Main Results:
- Conduction block was more pronounced in the endocardium and superior RA.
- Transmural CB in the inferior RA was linked to a higher incidence of post-operative AF.
- EEA was significant, particularly in the superior RA, and associated with hypertension, diabetes, hypercholesterolemia, and a history of persistent AF.
Conclusions:
- Significant endo-epicardial differences in conduction disorders and EEA exist even during sinus rhythm.
- These electrical abnormalities are exacerbated by cardiovascular risk factors and a history of persistent AF.
- Findings offer critical insights into atrial excitation complexity and its implications for AF.
Abstract:
Background The significance of endo-epicardial asynchrony (EEA) and atrial conduction block (CB), which play an important role in the pathophysiology of atrial fibrillation (AF) during sinus rhythm is poorly understood. The aim of our study was therefore to examine 3-dimensional activation of the human right atrium (RA). Methods and Results Eighty patients (79% men, 39% history of AF) underwent simultaneous endo-epicardial sinus rhythm mapping of the inferior, middle and superior RA. Areas of CB were defined as conduction delays of ≥12 ms, EEA as activation time differences of opposite electrodes of ≥15 ms and transmural CB as CB at similar endo-epicardial sites. CB was more pronounced at the endocardium (all locations P<0.025). Amount, extensiveness and severity of CB was higher at the superior RA. Transmural CB at the inferior RA was associated with a higher incidence of post-operative AF (P=0.03). EEA occurred up to 84 ms and was more pronounced at the superior RA (superior: 27 ms [interquartile range, 18.3-39.3], versus mid-RA: 20.3 ms [interquartile range, 0-29.9], and inferior RA: 0 ms [interquartile range, 0-21], P<0.001). Hypertension (P=0.009), diabetes mellitus (P=0.018), and hypercholesterolemia (P=0.015) were associated with a higher degree of EEA. CB (P=0.007) and EEA (P=0.037) were more pronounced in patients with a history of persistent AF compared with patients without AF history. Conclusions This study provides important insights into complex atrial endo-epicardial excitation. Significant differences in conduction disorders between the endo- and epicardium and a significant degree of EEA are already present during sinus rhythm and are more pronounced in patients with cardiovascular risk factors or a history of persistent AF.
