IJCS | Volume 31, Nº6, November / December 2018

631 Felix et al. RV function by 2D strain in left-sided valve disease Int J Cardiovasc Sci. 2018;31(6)630-642 Original Article inflow and outflow chambers which may be adequately visualized only from separate views, load-dependency, and influence of ventricular interdependency. 5,6 In some pathologic conditions where changes in preload (e.g. severe tricuspid regurgitation) and afterload (e.g. pulmonary hypertension) are seen, the evaluation of RV function is particularly difficult. In patients with severe VHD, RV function assessment is challenging, not only because of the hemodynamic alterations frequently seen in these patients, but also because its primary etiopathogenic process itself may impair RV function, as we often see in rheumatic heart disease. 7 In the last few years, studies have shown the applicability and clinical value of three-dimensional echocardiography (3DE) and two-dimensional strain (2DS) techniques in the evaluation of RV systolic function, with good accuracy for detecting RV dysfunction, and additional prognostic value in various diseases. 8 Speckle- tracking echocardiography (STE) derived techniques, specially 2DS, allows myocardial deformation analysis, is less dependent on angle and loading conditions, with great potential for RV evaluation (considering the complex geometry of the RV and great exposure to load changes), and has been shown to be a very sensitive technique, allowing early detection of subclinical RV involvement in a great variety of diseases. 9-12 Real-time 3DE is a well-established echocardiographic technique that has the great advantage of displaying the entire right ventricle in a single dataset, despite its irregular shape. The technique, hence, overcomes inherent limitations of tomographic methods for assessment of ejection fraction (EF), with good accuracy when compared with cardiac magnetic resonance (CMR). 13-17 Objectives The aim of this study was to analyze RV systolic function in patients with severe left-sided VHD using conventional echocardiography and 2DS techniques, testing the correlation of these techniques with RV ejection fraction (RVEF) measured by 3DE, and to evaluate the accuracy of these three techniques for the detection of RV dysfunction (RVEF < 44%). Methods This prospective observational cross-sectional study was approved by the local ethics committee. Study population From May 2013 to May 2014, in a tertiary cardiology hospital, we recruited consecutive adult patients with diagnosis of severe mitral and/or aortic valve disease 18 referred for preoperative evaluation for cardiac surgery (valve replacement, repair or both). We only included patients with no previous history of cardiac surgery, to avoid the influence of pericardiotomy on the accuracy of echocardiographic parameters of RV systolic function, and patients with no history of coronary artery disease to avoid confounding factors in determining the cause and severity of pulmonary hypertension and RV disease. We excluded patients with poor echocardiographic window for analysis of RV systolic function (either conventional parameters or 2DS), patients with severe tricuspid regurgitation (TR) and those who refused to participate in the study. Conventional echocardiography Echocardiography was performed using standard views, with the patient in the left lateral decubitus position, using a commercially available ultrasound machine (Vivid E9, GE Healthcare, Horten, Norway). Conventional echocardiographic images and cine loops of all patients were obtained by a single experienced examiner using a M5S transducer. Left ventricular (LV) EF was calculated using the biplane method of discs, and all the Doppler parameters necessary to quantitate the severity of valvular lesions and pulmonary artery systolic pressure (PASP) were obtained and analyzed in accordance with the criteria defined on the EAE/ASE/ EACVI guidelines. 19,20 RV diastolic and systolic areas were measured to calculate RV fractional area change (FAC). With the pulsed-wave Doppler sample volume positioned at the lateral tricuspid annulus in the RV focused apical 4-chamber view, the peak systolic velocity (PSV) by tissue Doppler was obtained. We alsomeasured the tricuspid annular plane systolic excursion (TAPSE), placing theM-mode cursor through the base of the lateral tricuspid annulus, quantitating its longitudinal motion at peak systole. Speckle-tracking echocardiography For STE analysis, digital loops of the right ventricle were obtained from apical 4-chamber and/or right ventricle-focused apical 4-chamber views. Three cardiac cycles were acquired from each view at a frame rate of