Assessment of Right Ventricular Function in Pulmonary Hypertension with Multimodality Imaging

Abstract

Pulmonary hypertension (PH) is defined as resting mean pulmonary artery pressure ≥ 25 mmHg and is caused by multiple etiologies including heart, lung or other systemic diseases. Evaluation of right ventricular (RV) function in PH is very important to plan treatment and determine prognosis. However, quantification of volume and function of the RV remains difficult due to complicated RV geometry. A number of imaging tools has been utilized to diagnose PH and assess RV function. Each imaging technique including conventional echocardiography, three-dimensional echocardiography, strain echocardiography, computed tomography and cardiac magnetic resonance imaging has-advantages and limitations and can provide unique information. In this article, we provide a comprehensive review of the utility, advantages and shortcomings of the multimodality imaging used to evaluate patients with PH.

Keywords: Computed tomography; Echocardiography; Magnetic resonance imaging; Pulmonary hypertension; Right ventricle.

Figure 1. Methods of analysis of right ventricular (RV) structures and RV function. (A) RV dimension is measured at the basal level in the four-chamber view. RV fractional area change can be calculated as (RV end-diastolic area [RVEDA] - RV end-systolic area [RVESA]) / RVEDA × 100) and, is a simple way to evaluate RV systolic function. (B) RV thickness more than 5 mm is suspicious of RV hypertrophy secondary to pulmonary hypertension. (C) Tricuspid annular plane systolic excursion (TAPSE) is the distance of the tricuspid annulus during the cardiac cycle using M-mode. (D) The peak systolic velocity of the lateral tricuspid annulus (S′) is measured by pulsed tissue Doppler imaging.

Figure 2. Real-time three-dimensional echocardiography images using a commercially available system (EchoPAC PC, TomTec Imaging, Inc., Munich, Germany). (A) 3D images of RV are acquired in the RV focused four-chamber view. (B) Alignment of the LV / RV axis is based on the mitral valve, tricuspid valve, and apex. Aortic annulus and junction of the ventricle should be pointed identified manually. (C) Contour revision is edited at end-diastolic phase in four-chamber and short axis views from base to apex. (D) RV volume and RV function are measured by automatic analysis. LV: left ventricle, RV: right ventricle.

Figure 3. Longitudinal strain measured by two-dimensional speckle tracking echocardiography. (A) Right ventricular global longitudinal strain (RVGLS) is −23% with normal global RV function. (B) RVGLS is −14% suggestive of decreased RV function.

Figure 4. CT findings of pulmonary hypertension (PH). (A) Dilatation of the main pulmonary artery (MPA) and an MPA to ascending aorta (AA) diameter ratio > 1 are highly suspicious of PH. (B) Right ventricular dilation, hypertrophy, flattening and bowing of the interventricular septum are seen.