Assessment of the relationship between functional capacity and right ventricular ultrasound tissue characterization by integrated backscatter in patients with isolated mitral stenosis

Diagnosis and Pathophysiological Mechanisms of Group 3 Hypoxia-Induced Pulmonary Hypertension

PURPOSE OF REVIEW

Group 3 hypoxia-induced pulmonary hypertension (PH) is an important and increasingly diagnosed condition in both the pediatric and adult population. The majority of pulmonary hypertension studies to date and all three classes of drug therapies were designed to focus on group 1 PH. There is a clear unmet medical need for understanding the molecular mechanisms of group 3 PH and a need for novel non-invasive methods of assessing PH in neonates.

RECENT FINDINGS

Several growth factors are expressed in patients and in animal models of group 3 PH and are thought to contribute to the pathophysiology of this disease. Here, we review some of the findings on the roles of vascular endothelial growth factor A (VEGFA), platelet-derived growth factor B (PDGFB), transforming growth factor-beta (TGFB1), and fibroblast growth factors (FGF) in PH. Additionally, we discuss novel uses of echocardiographic parameters in assessing right ventricular form and function. FGF2, TGFB, PDGFB, and VEGFA may serve as biomarkers in group 3 PH along with echocardiographic methods to diagnose and follow right ventricle function. FGFs and VEGFs may also function in the pathophysiology of group 3 PH.

Analysis of Regional Right Ventricular Function by Tissue Doppler Imaging in Patients with Aortic Stenosis

Background:

Right ventricular (RV) dysfunction is frequently observed in patients with aortic stenosis (AS). Nevertheless, assessment of regional RV deformation is yet not performed. The aim of the study was to analyze the impact of moderate and severe AS on global and regional RV function by a multisegmental approach using tissue Doppler imaging (TDI).

Methods:

In 50 patients (Group I – AS [n = 25] and Group II – normal controls [n = 25]), additional echocardiographic views of the RV were prospectively performed. The TDI sample volume was placed in the basal myocardial region of the anterior (RV-anterior), inferior (RV-inferior), and free RV wall (RV-free wall) to assess the following parameters: S'_RV, E'_RV, and A'_RV waves; IVCT_RV; IVRT_RV; and myocardial performance index (MPI_RV).

Results:

In AS patients, left ventricular (LV) mass index, left atrial (LA) volume index, and LV end-diastolic pressure were significantly increased. Moreover, AS patients had higher systolic pulmonary artery pressure (sPAP) and lower values for PV AccT (P < 0.0001), but TAPSE was not different between the two groups (P = 0.062). In AS patients, IVRT_RV-anterior, IVRT_RV-inferior, and IVRT_RV-freewall and MPI_RV were statistically increased (P < 0.0001). A significant correlation between IVRT_RV (evaluated at all three regions) and the parameters including sPAP, PV AccT, and E_LV/e'_LV ratio was observed in AS. A strong correlation was observed between IVRT_{RV-freewall/inferior} and AS severity by evaluation of velocities, gradient, and aortic valve area (P < 0.0001).

Conclusions:

The present study reports a correlation between the severity of AS and the increase of IVRT_RV and MPI_RV. Thus, a distinct analysis of RV performance is important for echocardiographic evaluation of patients with AS.

Novel methods for assessment of right heart structure and function in pulmonary hypertension

Long-term increases in pulmonary vascular resistance and pulmonary arterial pressure resulting from structural alterations and abnormal vasoreactivity of the pulmonary vasculature may lead to right ventricular (RV) remodeling. Conventional methods of assessment of RV structure and function do not provide sensitive markers of RV remodeling for prognostic information. Advances in cardiac imaging have provided the capability to obtain quantitative information on the RV structure and function. This article reviews the clinical conditions that result in PH and discusses the novel and emerging methods for the assessment of right heart structure and function in PH in infants and children.