Impact of reduced left atrial functions on diagnosis of paroxysmal atrial fibrillation: Results from analysis of time-left atrial volume curve determined by two-dimensional speckle tracking

Background: Atrial fibrillation is commonly associated with impaired reservoir and booster functions of the left atrium (LA). Recent advances in two-dimensional speckle tracking technique (2DST) enabled automatic analysis of the time-LA volume curve representing these functions. Our objective was to evaluate LA function in patients with or without paroxysmal atrial fibrillation (PAF) using 2DST. Methods: We studied 111 patients (68 men, age 62 ± 16 years) with (n= 53) or without (n= 58) PAF. After constructing time-LA volume curves from the apical four and two chamber views (iE33, Philips with QLAB 6.0, Philips Medical Systems, Bothell, WA, USA), maximal LA volume (LAVmax), preatrial contraction LA volume (LAVpreA), and minimum LA volume (LAVmin) were obtained. Then, LA reservoir volume (ARV = LAVmax - LAVmin) and active emptying volume (AEV = LAVpreA - LAVmin) were calculated to determine ARV/LAVmax as reservoir function and AEV/LAVpreA as booster pump function. Results: PAF was associated with greater LAVmax than that in controls (80 ± 21. ml versus 65 ± 16. ml, p< 0.001) and with reduced reservoir and booster functions (ARV/LAVmax 46 ± 9% versus 52 ± 7%; AEV/LAVpreA 29 ± 10% versus 36 ± 6%, p< 0.001). Multivariate logistic analysis demonstrated that ARV/LAVmax and AEV/LAVpreA were closely associated with the existence of PAF. Conclusion: These results demonstrate that the present 2DST enables determining LA reservoir and booster functions, providing insights into the diagnosis of PAF.