Related Experiment Video
Updated: Aug 7, 2025
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Intracardiac energy inefficiency during atrial fibrillation rhythm with heart failure: Assessment by echo-vector flow
Tetsuma Kawaji1, Hiroki Shiomi2, Bingyuan Bao3
1Department of Cardiology, Mitsubishi Kyoto Hospital, Kyoto, Japan; Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Insights
Intracardiac energy loss during atrial fibrillation (AF) is higher in heart failure (HF) patients with elevated NT-proBNP. Sinus restoration therapy improved this energy inefficiency, suggesting a link between intracardiac dynamics and HF severity in AF.
Area of Science:
- Cardiology
- Medical Imaging
- Fluid Dynamics
Background:
- Intracardiac dynamics in atrial fibrillation (AF) complicated by heart failure (HF) remain incompletely understood.
- Echo-vector flow mapping offers a novel approach to assess these dynamics.
Purpose of the Study:
- To evaluate the impact of intracardiac dynamics, assessed by echo-vector flow mapping, on AF patients with concomitant HF.
- To correlate intracardiac energy loss (EL) with NT-proBNP levels, a marker of HF severity.
Main Methods:
- Seventy-six AF patients undergoing sinus restoration therapy were studied.
- Energy loss (EL) was measured using echo-vector flow mapping during both AF and sinus rhythms.
- Patients were stratified into high (≥1800 pg/ml) and low NT-proBNP groups.
Main Results:
- Higher average EL/stroke volume (SV) in the left ventricle (LV) and left atrium (LA) during AF rhythm was observed in the high NT-proBNP group compared to the low NT-proBNP group.
- Patients with high NT-proBNP exhibited significant vortex formation and extreme EL in the LV and LA during diastole.
- A greater average decrease in EL/SV in the LV and LA was noted in the high NT-proBNP group after sinus restoration.
Conclusions:
- Elevated intracardiac energy loss during AF rhythm signifies energy inefficiency and is associated with higher serum NT-proBNP levels.
- Sinus restoration therapy demonstrated an improvement in intracardiac energy inefficiency in AF patients with HF.
- These findings highlight the utility of echo-vector flow mapping in understanding AF pathophysiology in the context of HF.
Aims:
Intracardiac dynamics during atrial fibrillation(AF) complicated by heart failure(HF) are not fully understood. The aim of this study was to evaluate the impact of intracardiac dynamics assessed by echo-vector flow mapping on AF complicated by HF.
Methods And Results:
We enrolled 76 AF patients receiving sinus restoration therapy and assessed energy loss(EL) by echo-vector flow mapping during both AF rhythm and sinus rhythm. Patients were divided into 2 groups according to serum NT-proBNP level: high NT-proBNP group(≥1800 pg/ml during AF rhythm: N = 19), and low NT-proBNP group(N = 57). Outcome measures were average ELs/stroke volume(SV) in left ventricle(LV) and left atrium(LA). Average EL/SVs during AF rhythm in the LV and LA were significantly larger in the high NT-proBNP group than the low NT-proBNP group(54.2 mE/m·L versus 41.2 mE/m·L, P = 0.02; 3.2 mE/m·L versus 1.9 mE/m·L, P = 0.01). The significantly larger EL/SV in the high NT-proBNP group was recorded for maximum EL/SVs. In patients with high NT-proBNP, large vortex formation with extreme EL was detected in the LV and LA during the diastolic phase. After sinus restoration, the average decrease of EL/SV in the LV and LA was larger in the high NT-proBNP group(-21.4 mE/m·L versus +2.6 mE/m·L, P = 0.04; -1.6 mE/m·L versus -0.3 mE/m·L, P = 0.02). Average EL/SV during sinus rhythm did not significantly differ between the high and low NT-proBNP groups in the LV and LA.
Conclusions:
High EL during AF rhythm as intracardiac energy inefficiency was associated with high serum NT-proBNP levels and improved after sinus restoration.
