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Fractionated atrial electrograms during sinus rhythm: relationship to age, voltage, and conduction velocity
Kurt C Roberts-Thomson1, Peter M Kistler, Prashanthan Sanders
1Department of Cardiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia.
Insights
Fractionated atrial electrograms (CFAEs) increase with age, particularly in older adults. These electrograms correlate with lower atrial voltage and slower conduction, suggesting architectural changes influence their morphology.
Area of Science:
- Electrophysiology
- Cardiac Anatomy
- Geriatric Cardiology
Background:
- Fractionated atrial electrograms (CFAEs) are linked to atrial fibrillation (AF) mechanisms.
- The prevalence and distribution of CFAEs in healthy individuals remain underexplored.
Purpose of the Study:
- To investigate the impact of aging on CFAEs.
- To examine the relationship between CFAEs and the atrial substrate.
Main Methods:
- Electroanatomic mapping of the right atrium (RA) in 21 patients without structural heart disease.
- Patients were stratified into three age groups: <30, 31-59, and >60 years.
- Analysis of CFAE proportion, mean atrial voltage, and conduction velocity across different RA regions.
Main Results:
- CFAEs were significantly more prevalent in the >60 years group compared to the <30 years group (14.6% vs. 2.7%).
- CFAEs predominantly localized to the posterior and high septal RA.
- A positive correlation was found between CFAEs and age (R=0.72), and negative correlations with atrial voltage (R=-0.57) and conduction velocity (R=-0.73).
Conclusions:
- CFAEs increase with age, associated with reduced atrial voltage and slowed conduction.
- The distribution of CFAEs in the posterior and high septal RA suggests myocardial architecture influences electrogram morphology.
- Age-related changes in atrial substrate contribute to CFAE development.
Background:
Fractionated atrial electrograms (CFAEs) have been implicated in the mechanism of atrial fibrillation (AF). The prevalence and distribution of CFAEs in normal populations have not been clearly defined.
Objective:
This study sought to determine the influence of age on CFAEs and investigate the relationship between CFAEs and the underlying atrial substrate.
Methods:
Twenty-one patients without structural heart disease underwent electroanatomic mapping of their right atrium (RA). Patients were categorized into 3 groups according to age: group A, patients <30 years (25.1 +/- 3.1 years, n = 7); group B, patients between 31 and 59 years (51.7 +/- 10.3 years, n = 6); group C, patients >60 years (66.9 +/- 7.7 years, n = 8). The proportion of points with CFAEs was analyzed for the high and low septal RA, high and low lateral RA, and high and low posterior RA. The mean atrial voltage and conduction velocity were assessed in each of these regions.
Results:
The percentage of CFAEs was greater in group C (14.6% +/- 7.7%) than in group A (2.7% +/- 2.1%; P = 0.001). The percentage of CFAEs in group B (8.5% +/- 3.5%) was not significantly different from that in group A (P = 0.21) and group C (P = 0.14). The CFAEs were predominantly located in the posterior RA and high septal RA. There were significant correlations between the proportion of CFAEs and age (R = 0.72; P < 0.01), atrial voltage (R = -0.57; P < 0.01), and conduction velocity (R = -0.73; P < 0.001).
Conclusion:
CFAEs increase with age and occur in regions of low atrial voltage and slowed conduction. The distribution of CFAE is predominantly along the posterior and high septal RA, regions where there are marked changes in myocardial fiber orientation. This suggests that the underlying myocardial architecture is the main influence on electrogram morphology.
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