Intracardiac Energy Inefficiency During Atrial Fibrillation Rhythm with Heart Failure: Assessment by Echo-Vector Flow Mapping.

Aims: Intracardiac dynamics during atrial fibrillation(AF) complicated by heart failure(HF) are not fully un-derstood. 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 center dot L versus 41.2 mE/m center dot L, P = 0.02; 3.2 mE/m center dot L versus 1.9 mE/ m center dot 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 center dot L versus +2.6 mE/m center dot L, P = 0.04;-1.6 mE/m center dot L versus-0.3 mE/m center dot 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.