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Improvement in left ventricular function by ablation of atrioventricular nodal conduction in selected patients with
L M Rodriguez1, J L Smeets, B Xie
1Department of Cardiology, Academic Hospital Maastricht, The Netherlands.
Insights
Atrial fibrillation (AF) can impair left ventricular (LV) function, especially with longer durations. Ablation of atrioventricular conduction improves LV function in affected patients, highlighting the importance of rate control.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Imaging
Background:
- Lone atrial fibrillation (AF) can lead to left ventricular (LV) dysfunction.
- Drug therapy often fails to adequately control ventricular rate or prevent AF recurrence.
- The impact of AF duration on LV function requires further investigation.
Purpose of the Study:
- To assess changes in left ventricular (LV) function before and after atrioventricular conduction ablation in patients with lone atrial fibrillation (AF).
- To determine if the duration of AF influences the reversibility of LV dysfunction after ablation.
Main Methods:
- Echocardiography was used to measure LV ejection fraction, LV dimensions, and left atrial dimensions in 30 patients with lone AF before and after ablation.
- Patients were divided into two groups based on LV ejection fraction (< or = 50% and > 50%) before ablation.
- Statistical analysis compared parameters between groups and before/after ablation.
Main Results:
- In patients with impaired LV function (ejection fraction <= 50%), ablation significantly improved LV ejection fraction and reduced LV and left atrial dimensions.
- No significant changes in LV function or dimensions were observed in patients with preserved LV function (> 50%) after ablation.
- A longer duration of AF was significantly associated with impaired LV function prior to ablation.
Conclusions:
- Lone atrial fibrillation (AF), particularly when prolonged, can cause reversible left ventricular (LV) dysfunction.
- Ablation of atrioventricular conduction to achieve ventricular rate control can significantly improve LV function in these patients.
- Duration of AF is a critical factor in the development and potential recovery of LV dysfunction.
Abstract:
Left ventricular (LV) function was studied in 30 patients with lone atrial fibrillation (AF) (paroxysmal [n = 27] and persistent [n = 3]) before and after ablation of atrioventricular conduction. In all patients, drug treatment did not control ventricular rate during AF or prevent recurrences of the arrhythmia, or both. LV ejection fraction, and LV end-systolic and end-diastolic, and left atrial dimensions were measured by echocardiography before (mean 7 +/- 10 months, range < 1 to 37) and after (14 +/- 20 months, < 1 to 77) ablation. Before ablation, LV ejection fraction was < or = 50% in 12 patients (group I) and > 50% in 18 (group II). After ablation, LV ejection fraction increased significantly in group I from 43 +/- 8% to 54 +/- 7% (p < 0.0001). There were also significant decreases in LV-end systolic and end-diastolic, and left atrial dimensions. No changes in these parameters were observed in group II. Groups I and II had a significant difference in the duration of AF (group I: mean 11 years, range 8 to 28; and group II: 5 years, 2 to 14) (p < 0.05). No difference was present in age, sex, New York Heart Association functional class for dyspnea, or type of ablation procedure. Thus, some patients with lone AF may show deterioration of LV function, which appears to be related to the duration of the arrhythmia; in these cases, LV function may improve significantly after ventricular rate control is accomplished by ablation of atrioventricular conduction.