ABC | Volume 111, Nº1, July 2018

Original Article Luo et al Right ventricular function by 2D-STE in SLE Arq Bras Cardiol. 2018; 111(1):75-81 Table 2 – Comparison of conventional parameters between systemic lupus erythematosus patients (groups B, C and D) and control group (Group A) ( x ± s ) Parameters Group A (n = 30) Group B (n = 37) Group C (n = 34) Group D (n = 31) Reference normal value @ LVEF, % 64.51 ± 3.11 63.69 ± 6.61 62.11 ± 4.87 63.01 ± 4.86 ≥ 50 RVAW, cm 0.36 ± 0.05 0.40 ± 0.03 0.43 ± 0.06 0.69 ± 0.09 $*# 0.1-0.5 RVED, cm 2.98 ± 0.43 3.11 ± 0.45 3.22 ± 0.39 3.65 ± 0.36 $*# 1.9-3.5 TAPSE, cm 2.24 ± 0.21 2.21 ± 0.19 1.76 ± 0.22 1.2 ± 0.18 $*# > 1.7 RV FAC, % 50.45 ± 4.67 49.24 ± 4.81 42.69 ± 5.07 34.43 ± 3.95 $*# > 35 Pulsed Doppler S wave, cm/s 13.35 ± 2.14 12.92 ± 1.90 11.48 ± 2.06 9.33 ± 1.81$*# > 9.5 RV 3D EF, % 46.18 ± 2.28 45.80 ± 2.21 44.34 ± 2.14 31.19 ± 4.36$*# ≥ 40 LVEF: left ventricular ejection fraction; RVAW: right ventricular anterior wall thickness; RVED: right ventricular end-diastolic diameter; TAPSE: tricuspid annulus peak systolic excursion; RV FAC: right ventricular fractional area curve; Pulsed Doppler S wave: peak systolic velocity of tricuspid annulus by pulsed-wave tissue Doppler imaging; RV 3D EF: three-dimensional echocardiographic right ventricular ejection fraction. $ : p < 0.05 vs. group A. * : p < 0.05 vs. group B. # : p < 0.05 vs. group C. Chinese guidelines provide different reference normal values as compared with international guidelines. Table 3 – Comparison parameters of strain rate and strain of the SLE patients with the control group ( x ± s ) strain Group A (n = 30) Group B (n = 37) Group C (n = 34) Group D (n = 31) ε, % Basal -33.87 ± 5.89 -32.19 ± 7.38 -25.77 ± 7.67 ↑* -19.55 ± 4.89 $*# Middle -31.67 ± 7.00 -29.09 ± 7.30 -22.89 ± 8.05 ↑* -17.67 ± 6.83 $*# Apical -25.45 ± 6.99 -27.51 ± 2.47 -19.64 ± 8.65 ↑* -15.91 ± 6.33 $*# SRs, s -1 Basal -2.33 ± 0.34 -2.43 ± 0.44 -1.84 ± 0.41 ↑* -1.73 ± 0.47 $* Middle -1.78 ± 0.34 -1.67 ± 0.56 -1.59 ± 0.37 ↑* -1.36 ± 0.31 $* Apical -1.53 ± 0.54 -1.54 ± 0.55 -1.33 ± 0.38 ↑* -1.16 ± 0.36 $* SRe, s -1 Basal 2.44 ± 0.74 2.43 ± 0.69 1.95 ± 0.49 ↑* 1.85 ± 0.52 $* Middle 2.04 ± 0.58 2.06 ± 0.49 1.73 ± 0.54 ↑* 1.66 ± 0.46 $* Apical 1.84 ± 0.69 1.83 ± 0.67 1.33 ± 0.65 ↑* 1.29 ± 0.55 $* SRa, s -1 Basal 1.66 ± 0.64 1.63 ± 0.66 1.44 ± 0.56 ↑* 1.42 ± 0.55 $* Middle 1.55 ± 0.70 1.56 ± 0.65 1.28 ± 0.41 ↑* 1.21 ± 0.52 $* Apical 1.88 ± 0.49 1.85 ± 0.67 1.60 ± 0.56 ↑* 1.54 ± 0.54 $* SRs: systolic strain rate; SRe: early diastolic strain rate; SRa: late diastolic strain rate $ : p <0.05 vs. group A. *: p < 0.05 vs. group B. # : p < 0.05 vs. group C. and SR represents ventricular contractility. 27 This means that the degrees of RV deformation in groups C and Dwere significantly lower compared with groups A and B, and significantly lower in group D than in group C. This implies that the RV function of both groups C and D was impaired, and this was more severe in group D. This is in accordance with the findings of Pirat et al., 28 The discrepancy of ε and SR between groups C and D in this study might be related to the significant differences in HR and PASP in these groups. While SR has been shown to be independent of load, HR and other factors, an increased HR and altered load changes have been associated with reduced ε . 17-20 The impaired RV function of group C (mild PH group) was detected early by 2D-STE-derived strain and SR imaging compared with the conventional echocardiography. Study limitations There were several limitations of this study. First, PH was not determined via right heart catheterization, but estimated by echocardiography. Second, RV was not assessed by cardiac magnetic resonance for the sake of comparison. However, these might not be a limitation of this study, because it aimed to evaluate and compare the RV function of SLE patients with different degrees of PH estimated by 2D-STE-derived strain and SR imaging. Third, clinical data of SLE patients, such as antiphospholipid antibodies were not collected. Also, estimation of PH by 2D-STE may be influenced by factors, such as patient’s breathing pattern. Finally, some participants such as obese patients may not be able to use this method, because it requires high-resolution image quality. 78