Abstract
Introduction: Four-dimensional (4-D) flow cardiac magnetic resonance imaging can be used to elegantly describe the hemodynamic efficiency of left ventricular (LV) flow throughout the cardiac cycle. Patients with nonvalvular paroxysmal atrial fibrillation (PAF) may have occult LV disease. Flow distribution analysis, based on 4-D flow, may unmask the presence of LV disease by assessing flow components: direct flow, retained flow, delayed ejection, and residual volume. This study aimed to identify LV hemodynamic inefficiencies in patients with PAF and normal systolic function. We hypothesized that the fraction of direct flow to the total end-diastolic volume would be reduced in patients with PAF compared with controls. Methods: We used 4-D LV flow component analysis to compare hemodynamics in 30 healthy controls and 50 PAF patients in sinus rhythm. Results: PAF subjects and healthy controls had similar LV mass, volume, and ejection fraction. Direct flow was lower in the PAF group than in the controls (44.5 ± 11.2% vs. 50.0 ± 12.2%, p = 0.042) while delayed ejection was higher in the PAF group (21.6 ± 5.6% vs. 18.6 ± 5.7%, p = 0.022). Conclusion: PAF patients demonstrated a relative reduction in direct flow and elevation in delayed ejection.
Highlights
Four-dimensional (4-D) flow cardiac magnetic resonance imaging can be used to elegantly describe the hemodynamic efficiency of left ventricular (LV) flow throughout the cardiac cycle
Direct flow was lower in the paroxysmal atrial fibrillation (PAF) group than in the controls (44.5 ± 11.2% vs. 50.0 ± 12.2%, p 0.042) while delayed ejection was higher in the PAF group (21.6 ± 5.6% vs. 18.6 ± 5.7%, p 0.022)
PAF patients demonstrated a relative reduction in direct flow and elevation in delayed ejection
Summary
Four-dimensional (4-D) flow cardiac magnetic resonance imaging can be used to elegantly describe the hemodynamic efficiency of left ventricular (LV) flow throughout the cardiac cycle. LV flow component analysis has been largely used to study hemodynamic efficiencies of healthy subjects and patients with heart failure (Eriksson et al, 2010; Stoll et al, 2019) In this method, blood that flows through the LV during a heart cycle is separated into four components (Figure 1) (Bolger et al, 2007). Residual volume is that blood stays in the LV for more than one cycle This method has been applied in AF referral populations to study LV function recovery after cardioversion (Karlsson et al, 2019); direct comparison of these novel hemodynamic markers has not been studied between AF patients versus healthy subjects. Given the expanding clinical burden of AF patients’ heart failure with preserved ejection fraction (HFpEF) among patients (Savarese and Lund, 2017), a detailed understanding of abnormalities in LV flow distribution within this patient population is strongly justified
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
