Right Ventricular Strain in Pulmonary Hypertension

Abstract

Since 2009, there have been ≥170 articles published in the cardiopulmonary literature on right ventricular (RV) echocardiographic strain imaging, including several in Circulation: Cardiovascular Imaging. Of particular interest has been the effort to use RV echocardiographic strain imaging to assess RV systolic function in pulmonary hypertension and the relationship of RV strain to disease severity and outcomes. In this issue of Circulation: Cardiovascular Imaging, Fine et al, 1 from the Mayo Clinic echo group, report on retrospectively evaluated data on the relationship of RV strain to outcomes in the largest such study to date, encompassing 575 patients with known or suspected pulmonary hypertension without elevated pulmonary venous pressure during a median follow-up period of 16.5 months.1 The data show a strong association between reductions in mean longitudinal strain and all-cause mortality, and cardiopulmonary mortality and cardiopulmonary events. An exhaustive biostatistical analysis shows the relationship to be quantitative, stronger than that of other echo indices including tricuspid annular plane systolic excursion, independent of clinical covariates and resulting in a significant improvement in predictive value when combined with relevant clinical variables, as reflected in a significant increase in the integrated discrimination improvement index and the c-statistic for the primary end point. Thus, the results promise to improve clinical risk assessment significantly for such patients and may improve clinical decision making. Article see p 711The apparent benefit is, in large part, a reflection of the relatively weak performance of older 2-dimensional (2D) echocardiographic indices of RV performance including fractional area change and tricuspid annular plane systolic excursion in this setting. RV imaging has been a minefield for echocardiography in adults since its inception. The complexity of ventricular shape, the thinness of the RV free wall, and the limitations in adults of transthoracic and subcostal windows in permitting full visualization of the RV, particularly in the setting of RV dilatation, have conspired to limit echo effectiveness. Thus, indices of RV size and function have failed by and large to make contributions commensurate with the importance of RV dysfunction in a number of settings in adult medicine. The advent of cardiac MRI (CMR) in the 1980s led to rapid development of volumetric 3D methods for left ventricular (LV) size, function, and mass followed shortly by methods for 3D LV strain imaging which continue to be regarded, even today, as the gold standards in the cardiovascular armamentarium. But even so, evaluation of RV volume and mass remained more variable than desirable whereas RV free wall strain assessment remained elusive with CMR until recent years.2 The advent of tissue Doppler and then speckle tracking echocardiographic strain imaging have led to the explosive development of applications of LV strain imaging since 2000, largely focused on the high sensitivity of LV s...

Echocardiographic and Hemodynamic Predictors of Survival in Precapillary Pulmonary Hypertension

“…[43][44][45] CI is largely controlled by venous return, which is determined by the difference between mean systemic venous pressure and RAP. Several authors 45,46 have suggested that RAP is a dependent variable, whereas venous return an independent variable because RAP decreased when cardiac output increases.…”

Noninvasive Imaging in the Assessment of the Cardiopulmonary Vascular Unit

“…In a recent editorial, Reichek 55 noted that there have been several hundred publications on RV myocardial imaging over the past few years. Considering this impressive body of literature, an obvious question is, How does myocardial deformation imaging affect screening or prediction of outcome in patients with PH?…”

The Right Ventricle under Pressure: Evaluating the Adaptive and Maladaptive Changes in the Right Ventricle in Pulmonary Arterial Hypertension using Echocardiography (2013 Grover Conference Series)

“…Looking at the movement of one side of the tricuspid annulus and measuring DTI from this region may not be as valuable once RV strain and 3D RVEF become more advanced and adopted. 61 However, many echocardiographic laboratories are currently using the conventional measures along with the newer methods described below for complete RV echocardiographic analysis. 62 …”

“…64 The normal and abnormal values still vary, depending on the vendor providing the strain software, which makes comparison between centers very difficult. 61 Worsening of RV longitudinal strain has been associated with increased pulmonary artery pressures, decreased TAPSE, worsened functional class, and increased mortality from PAH (Fig. 6).…”