Letter to the editor

Utility of three-dimensional global longitudinal strain of the right ventricle using transthoracic echocardiography for right ventricular systolic function in pulmonary hypertension

Right ventricular (RV) dysfunction is a predictor of adverse outcomes in patients with pulmonary arterial hypertension (PAH). Three-dimensional (3D) speckle-tracking echocardiography (STE) has been increasingly used to quantify RV function. However, the strain parameters evaluated by two-dimensional (2D) STE and 3D STE, which provide the most valuable clinical information, remain unknown. The purpose of our study was to investigate whether RV longitudinal strain (LS) provided a superior estimation of RV systolic performance and prognostic information compared with other strain vectors.

We prospectively studied 54 treatment-naïve patients with PAH and 35 normal controls. Pulmonary artery systolic pressure classified patients with PAH into three subgroups. Patients with PAH underwent echocardiography, cardiac magnetic resonance (CMR) imaging, 6-minute walking tests, and right-sided cardiac catheterization before and six months after vasodilator therapy. The 2D LS, 3D LS, circumferential strain (CS), and radial strain (RS) of RV free wall were calculated by 2D and 3D STE. RV ejection fraction (RVEF) was obtained from CMR. The patients were followed for a predefined endpoint of PAH-related hospitalization and death.

Our findings revealed that 2D and 3D LS showed significant reduction in mild PAH patients, whereas CS and RS were decreased in moderate and severe PAH patients. Right ventricular 3D LS had a similar correlation with CMR RVEF and hemodynamic parameters as 2D LS and the other strain vectors. The 2D and 3D LS improved 6 months after vasodilator therapy (P < .001 for both). After a median follow-up of 28 months, 20 patients had endpoint events. Receiver operating characteristic curve analysis demonstrated that RV 3D LS displayed a similar diagnostic performance for detecting adverse cardiac events as 2D LS (area under the curve: 0.84 vs 0.76, P = .11). Separate multivariable Cox analysis showed that RV 2D LS (hazard ratio [HR] = 1.19; 95% CI, 1.03～1.45; P = .01) and 3D LS (HR = 1.28; 95% CI, 1.08～1.52; P = .005) were significant predictors of adverse outcomes.

Patients with PAH show reduced RV strain. Two-dimensional and 3D LS can track clinical improvement following vasodilator therapy and provide valuable prognostic information.

Given that in patients with cardiac amyloidosis (CA), deposition of amyloid protein is not restricted to the left ventricular (LV) myocardium, it can be hypothesized that the diagnostic value of deformation mechanics would be enhanced by considering right ventricular (RV) strain measures. The aim of the present study was to examine the potential utility of left ventricular (LV) and right ventricular (RV) deformation and rotational parameters derived from three-dimensional speckle-tracking echocardiograph (3DSTE) to diagnose cardiac amyloidosis and differentiate this disease from other forms of myocardial hypertrophy.

Twenty-three patients with biopsy-proven light-chain (AL) amyloidosis, 23 patients with systemic arterial hypertension (HTN), 23 patients with hypertrophic cardiomyopathy (HCM), 23 athletes and 23 normal controls were prospectively studied by conventional echocardiography and 3DSTE. LV longitudinal strain (LV LS), LV circumferential strain (LV CS), RV global longitudinal strain and RV free-wall longitudinal strain (RV FW LS) were obtained by 3DSTE, as well as LV rotation and rotational velocities.

LV and RV longitudinal strains were reduced in cardiac amyloidosis (CA) patients compared to controls. By multivariate analysis, LV basal LS (p = 0.002), LV peak basal rotation (p = 0.003), and RV basal FW LS (p = 0.014) were independently associated with CA in the overall population. A significant improvement in global χ² value was noted with RV 3D-strain parameters over only LV-3DSTE + conventional indices for detection of CA (p < 0.001). Comparison of ROC curves showed that the AUC using combined LV basal LS, LV basal rotation and RV basal FW LS had a higher discriminative value than the other echocardiographic parameters used for detecting CA (AUC 0.93, 95%CI 0.81–0.97).

Three-dimensional speckle tracking echocardiography reveals regional and global biventricular dysfunction in CA. Assessment of RV ventricular dysfunction has an additive value in differentiating CA from other causes of myocardial wall thickening.

The dataset presented in this article is related to the research article entitled “Biventricular assessment of light-chain amyloidosis using 3D speckle tracking echocardiography: Differentiation from other forms of myocardial hypertrophy” (Vitarelli et al., 2018) [1], which examined the potential utility of left ventricular (LV) and right ventricular (RV) deformation and rotational parameters derived from three-dimensional speckle-tracking echocardiography (3DSTE) to diagnose cardiac amyloidosis(CA) and differentiate this disease from other forms of myocardial hypertrophy. The combined assessment of LV basal longitudinal strain, LV basal rotation and RV basal longitudinal strain had a high discriminative power for detecting CA. The data of this study provides more understanding on the value of LV 3DSTE deformation parameters as well as RV parameters in this particular cardiomyopathy.

The aim of our study was to assess the characterization of right ventricular (RV) deformation using three-dimensional (3D) speckle tracking echocardiography (STE) and association of 3D-STE indices with histologic and hemodynamic parameters in a chronic RV pressure overload animal model. Pulmonary artery banding (PAB) was used to induce RV pressure overload in seven beagles. 3D-STE, histologic and hemodynamic measurements were performed in PAB and sham-operated beagles 3 mo after PAB. RV longitudinal, radial and circumferential strain was measured from 3D-STE. Three mo after PAB, RV longitudinal strain was decreased; whereas radial and circumferential strain remained unchanged in PAB group. RV longitudinal strain was associated with interstitial fibrosis (r = −0.733) in the endocardial layer of the RV free wall. RV circumferential strain was related to dp/dt_max (r = 0.718). The significant correlations of RV 3D-STE indices with histologic and hemodynamic parameters indicate that 3D-STE may be a valuable tool for assessment of ventricular function in RV pressure overload.

Pulmonary hypertension (PH) is an important cause of morbidity and mortality in pediatric patients of diverse causes. Although advances in the understanding of pathology of pulmonary arterial hypertension have led to novel therapies, there is no cure for many forms of PH. Right ventricular function is a major determinant of prognosis in severe PH. The diagnosis of right heart failure is a clinical one but is supported by imaging and catheterization modalities. This chapter will discuss diagnosis of right ventricular failure in children, imaging of the right ventricle, and acute and chronic therapeutic options.

A new transthoracic echocardiography (TTE) technique allows multi-layer measurement of left ventricular (LV), endocardial, epicardial, and whole layer myocardial strain. We evaluated interobserver and intraobserver TTE reproducibility for 2D LV global longitudinal (GLS) and circumferential strain (GCS) estimates using data from severe aortic stenosis (AS) subjects with preserved LV ejection fraction (EF).

Twenty severe AS subjects (11 male; mean age, 75 ± 7 years; LV EF > 50%) underwent TTE (Vivid E9, GE Healthcare). Quantitative strain measurements of whole, endocardial, and epicardial layers were performed. GLS was defined as all 17 averaged LV segments, according to the American Heart Association classification. GCS was measured at the levels of the mitral valve, papillary muscle, and apex.

Interobserver correlation coefficients in whole, endocardial, and epicardial layers for GLS estimates were 0.81, 0.83, and 0.80, respectively, whereas those for GCS estimates were 0.38, 0.56, and 0.19, respectively, for the mitral valve, 0.44, 0.54, and 0.36, respectively, for the papillary muscle, and 0.55, 0.29, and 0.59, respectively, for the apex. Intraobserver correlation coefficients in whole, endocardial, and epicardial layers for GLS estimates were 0.97, 0.97, and 0.94, respectively, whereas those for GCS estimates were 0.86, 0.81, and 0.50 , respectively, for the mitral valve, 0.56, 0.72, and 0.28, respectively, for the papillary muscle, and 0.70, 0.69, and 0.62, respectively, for the apex.

In severe AS subjects with preserved LVEF, inter- and intra-observer TTE reproducibility in whole, endocardial, and epicardial layers were more consistent for 2D LV GLS than for 2D LVGCS.