IJCS | Volume 31, Nº6, November / December 2018

574 Table 2 - Global and regional peak left atrial strain ( Ɛ R) and strain rate (SR R ) during reservoir phase of the 12 segments before and after percutaneous closure of the left atrial appendage (LAA) Basal After LAA occlusion p Global Ɛ R, % 10.1 [8.1 - 14.7] 12.7 [5.4 - 16.5] 0.81 Lateral basal Ɛ R, % 18.6 [10.5 - 28.8] 17.6 [11.0 - 22.3] 0.49 Lateral mid Ɛ R, % 10.1 [6.0 - 18.8] 9.0 [4.4 - 16.4] 0.40 Lateral apical Ɛ R, % 7.1 [3.9 - 13.6] 5.9 [2.0 - 15.7] 0.84 Septal apical Ɛ R, % 9.1 [4.9 - 18.4] 8.5 [3.9 - 16.8] 0.38 Septal mid Ɛ R, % 12.0 [8.1 - 17.5] 9.8 [3.2 - 22.5] 0.86 Septal basal Ɛ R, % 13.2 [5.2 - 21.8] 12.2 [2.7 - 23.6] 0.84 Global SR R , s -1 1.06 ± 0.26 1.13 ± 0.34 0.38 Lateral basal SR R , s -1 1.14 ± 0.49 1.20 ± 0.62 0.60 Lateral mid SR R , s -1 1.04 ± 0.42 1.10 ± 0.56 0.61 Lateral apical SR R , s -1 1.18 ± 0.50 1.05 ± 0.48 0.41 Septal apical SR R , s -1 1.00 ± 0.54 1.10 ± 0.45 0.50 Septal mid SR R , s -1 0.94 ± 0.45 1.01 ± 0.29 0.45 Septal basal SR R , s -1 1.39 ± 0.53 1.35 ± 0.62 0.86 Ɛ R: left atrial strain during the reservoir phase; LAA: left atrial appendage; SR R : left atrial strain rate in the reservoir phase. Ɛ R values compared by the Mann-Whitney test and SR R values by the t-test. Figure 4 - Global left atrial strain ( Ɛ R) and strain rate during reservoir phase (SR R ) before and after percutaneous closure of the left atrial appendage. Differences between baseline and post-LAA occlusion device implantation data were analysed by paired sample t-test. Madeira et al. Atrial appendage closure and atrial performance Int J Cardiovasc Sci. 2018;31(6)569-577 Original Article Discussion Our investigation demonstrates that changes in left atrial fraction volume are minimal after LAA percutaneous closure, and mechanics of the left atrial reservoir phase assessed by 2D-STE are not significantly different before and after the procedure. Structural and functional remodelling of the left atrium has been proposed as a surrogate for diastolic dysfunction and a predictor of cardiovascular outcomes such as new-onset atrial fibrillation, stroke, heart failure, mortality after myocardial infarction, severity of diastolic dysfunction, and cardiovascular death. 12 2D-STE is a novel method for quantitative real-time assessment of regional myocardial deformation. The technology tracks acoustic speckles or kernels rather than using Doppler myocardial velocities. 17 Considering the limitations of the classical indices of left atrial function, assessment of Ɛ R by 2D-STE may represent a relatively rapid and easy-to- perform technique for assessing left atrial function, due to its semiautomated nature and off-line processing. In fact, in contrast to Doppler-derived parameters, 2D-STE has the advantage of being angle-independent, and less affected by reverberation, side lobe and drop-out artefacts. 18 Furthermore, recent studies have shown that 2D-STE is feasible and reproducible. 18-20 It has been suggested that Ɛ R allows an excellent assessment of the atrial deformation profile during an entire cardiac cycle,