ABC | Volume 111, Nº3, September 2018

Original Article Kanar et al RV function after pulmonary rehabilitation program Arq Bras Cardiol. 2018; 111(3):375-381 Figure 1 – Representative two-dimensional right ventricular strain images. Speckle-tracking apical four chamber view showing global and regional right ventricular longitudinal strain. L. Strain: Longitudinal strain. According to Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification; there were 22 class-II, 18 class-III, and 7 class-IV COPD patients. COPD patients had higher RV basal diameter, right atrial (RA) end-systolic area, sPAP, and MPI, as well as lower tricuspid annular plane systolic excursion (TAPSE) values compared to healthy control subjects in conventional echocardiographic measurements. In addition, there were significant differences in RV global LS and RV free wall LS between the two groups. In post-rehabilitation echocardiography and 6MWT assessments, there were significant improvements in RV speckle-tracking measurements (Table 2) and increase in 6MWT. In 2DE measurements, there were differences among sPAP, TAPSE, and MPI. However, sPAP was only statistically significant. RV free wall LS was directly related to distance walked at baseline 6MWT (r = 0.58, p < 0.001) and to 6MWTD∆ (r = 0.41, p = 0.04) (Figura 2). There were improvements of both BODE index and MRC parameters, but only the BODE index was statistically different. There was a statistically significant correlation between RV free wall LS and BODE index (r: 0.52, p < 0.001). Discussion In our study, we evaluated RV dysfunction in patients with moderate-to-very severe COPD in comparison with healthy subjects and also its improvement after PR program. In determination of both global and regional RV function improvement, STE was shown to be as effective as conventional 2DE. Moreover, RV global longitudinal strain was directly related to exercise tolerance determined by means of 6MWT and BODE index. Although the current available prognostic models for COPD do not include RV function, it might serve as a surrogate endpoint for determining mortality and morbidity rates in a variety of cardiopulmonary diseases. 15,16 On the other hand, RV assessment can be challenging. STE overcomes most of the limitations inherent in conventional 2DE, given that it is independent of cardiac translation, and it is angle- and load-independent, thus allowing accurate quantification of myocardial function. 17 STE also demonstrates whether reduced RV performance is due to a global failure or to localized impaired contraction. Moreover, it identifies discrete and localized losses in 377