Aortic Regurgitation Jet Increases Left Ventricular Energy Loss Associated With the Progression of Cardiac Failure　― A Vector Flow Mapping Analysis Study ―

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Background: Aortic valve regurgitation (AR) impairs cardiac function, but the underlying mechanisms remain unclear. Vector flow mapping (VFM) enables evaluation of blood flow patterns and energy loss in the left ventricle (LV). This study investigated the effect of AR on LV blood flow patterns, energy loss, and heart failure progression using VFM.

Methods and Results: Forty patients with severe AR undergoing aortic valve replacement (AVR) between January 2016 and March 2018 were included. Echocardiogram-based VFM in apical long-axis and 4-chamber views was performed before and after AVR, with results compared to a control group without valvular diseases (n=21). Preoperative LV energy loss due to an AR jet was significantly higher in patients with AR (median 8.7 J; interquartile range [IQR] 5.7–13.3 J) than in controls (1.7 J; IQR 0.7–2.6 J; P<0.001), and was positively correlated with preoperative serum B-type natriuretic peptide (BNP) concentrations (P=0.029). LV energy loss was not associated with LV systolic function or regurgitant volume, but was significantly affected by AR jet direction. Postoperatively, after AVR, LV energy loss (median 2.0 J; IQR 1.5–2.7 J) decreased to the same level as in the control group.

Conclusions: The regurgitant jet in severe AR increases LV energy loss, which is positively correlated with serum BNP concentrations, indicating that the AR jet contributes to the progression of heart failure through LV energy loss.