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 1 – Comparison of physiological 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) Mean age, years 42.1 ± 10.50 45.3 ± 8.40 41.3 ± 9.60 43.3 ± 7.50 DBP, mm Hg 80.32 ± 3.66 79.92 ± 3.19 79.78 ± 4.97 82.52 ± 3.89 SBP, mm Hg 130.95 ± 5.27 128.4 ± 5.94 125.85 ± 9.07 128.39 ± 8.58 HR, beats/min 69.92 ± 9.57 73.13 ± 10.87 74.09 ± 8.61 89.52 ± 12.01 $*# BSA, m 2 1.59 ± 0.26 1.67 ± 0.25 1.79 ± 0.38 1.66 ± 0.37 BMI, kg/ m 2 26.38 ± 2.28 25.26 ± 2.94 25.56 ± 3.81 26.22 ± 1.46 DBP: diastolic blood pressure; SBP: systolic blood pressure; HR: heart rate; BSA: body surface area; BMI: body mass index. $ : p < 0.05 vs. group A; * : p < 0.05 vs. group B; # : p<0.05 vs. group C. Conventional echocardiographic parameters There were no statistical differences in LVEF between the four groups. The RVAW and RVED were significantly higher in group D than in the other three groups, while TAPSE, RV FAC, pulsed Doppler S wave, and RV 3D EF were all significantly decreased in group D compared with the other groups. However, there were no significant differences in RVAW, RVED, TAPSE, RV FAC, pulsed Doppler S wave, and RV 3D EF between groups A, B and C (Seen in table 2). 2D-STE parameters The average of the longitudinal strain and SR of each segment in the basal, middle, and apical regions of the RV free wall was calculated in each group (Seen in table 3; Figure 1). We found that there were no significant differences in all the parameters between groups A and B. On the other hand, in groups C and D, ε , SRs, SRe and SRa of each segment were significantly decreased compared with groups A and B. The parameter ε of each segment in group D was also significantly lower than that in group C, although there were no significant differences in SRs, SRe and SRa of each segment between groups C and D. Discussion It has been previously demonstrated that RV function is a decisive factor for the severity and prognosis of SLE patients with PH, 15 and that 2D-STE-derived strain and strain rate imaging could precisely reflect deformation of RV myocardium, and detect the subclinical RV dysfunction. 16 Thereby, evaluation of RV function in SLE patients with PH is important for establishing treatment strategy, prevent clinical RV dysfunction and RV failure, and increase the survival rate of SLE patients with PH. To our knowledge, this has not been studied before. In the present study, we found that there were no significant differences in age, sex, BMI, BSA, SBP, andDBP between the four groups. Nevertheless, the HR in group Dwas significantly higher than that in the other three groups. It has been reported that HR could affect ε , and the increased HR was related to reduced ε , which represents the degree of deformation. 17-20 It also indicates that the degree of deformation of group D was decreased. The function of the RV is to maintain the normal blood flow of pulmonary circulation, which mainly depends on three factors: preload, contraction, and afterload. 21 PH is a common and devastating complication of SLE characterized by progressively increased pulmonary vascular resistance (PVR) and PASP. 22 Its mechanism is very complex and closely related to inflammation and the immune system. 23,24 In this study, we found that RVAW and RVED were significantly higher in group D than those in the other three groups, while TAPSE, RV FAC, pulsed Doppler S wave, and RV 3D EF were all significantly decreased in group D compared with the other groups. However, there were no significant differences in RVAW, RVED, TAPSE, RV FAC, pulsed Doppler S wave, and RV 3D EF between groups A, B and C. It demonstrates that the structure of the RV was remodeled in group D, and the RV myocardial systolic function was also impaired. We argue that long-standing increases in PASP in SLE patients with PH cause increased RV afterload, decreased pulmonary vascular compliance, and compensatory increases in RV contractility. Structurally, these results in expansion of the right ventricle and increased RV wall thickness for maintenance of RV function. 18,22,25 As PASP further increases, the impaired RV myocardium undergoes hypoxia, which causes enlarged RV volume, tricuspid valve insufficiency, and increased RV preload. This progresses to increased right atrial diameter and exacerbated myocardial impairment, leading to RV remodeling and decompensation, reduced RV contraction, and finally clinical RV dysfunction. 22,26 Based on conventional data, group D experienced clinical RV dysfunction. Decreased TAPSE, RV FAC and pulsed Doppler S wave also implied a bad prognosis, and decreased RV 3D EF even triggered the RV failure of patients in group D, while the RV function in group C was still normal. In this prospective study, based on the 2D-STE data, we found that ε , SRs, SRe and SRa of each segment were significantly decreased in groups C and D compared with groups A and B, while there were no significant differences in these parameters between groups A and B. The parameter ε of each segment in group D was also significantly lower than that in group C, although there were no significant differences in SRs, SRe and SRa of each segment between groups C and D. As mentioned before, ε represents the degree of deformation, 77