Evaluation of Right Ventricle by Speckle Tracking and Conventional Echocardiography in Rats With Right Ventricular Heart Failure

Abstract

SummarySpeckle tracking echocardiography (STE) has been reported to be a promising technique for evaluating right ventricular (RV) function in the clinical setting. On the other hand, the usefulness of STE for RV evaluation in small animal models has not been clarified, although the rat model is among the most commonly used animal models to develop novel effective treatments against pulmonary hypertension and RV heart failure (HF).We validated the use of STE and conventional echocardiographic variables for evaluating RV functions in a rat model by comparing the echocardiographic values of RVHF rats (n = 12) induced by monocrotaline injection with those of control rats (n = 12).Most conventional echocardiographic variables demonstrated that RVHF rats have significant RV dysfunction. The area under the curve (AUC) values to distinguish RV dysfunction in RVHF rats from normal RV function in control rats using fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), peak tissue Doppler tricuspid annular velocities at systole (Sa), and at early diastole (Ea) were 0.71, 0.98, 0.79, 0.92, and 0.91, respectively. However, using STE analysis for RV evaluation, limited reproducibility was observed (variability 19-37 %, ICC 0.74-0.88) and the only circumferential strain showed significantly lower absolute values (P = 0.039, AUC = 0.76).To evaluate RV function in rat models, circumferential strain may be useful, however, the reproducibility and diagnostic utility were limited. Conventional echocardiographic variables such as TAPSE, tissue Doppler Sa, and Ea have superior diagnostic utility. ( heart failure (HF) is associated with poor prognosis, and current therapies are still unsatisfactory for treating this condition. To elucidate its pathophysiology and develop effective treatments, experiments using appropriate animal models are needed. The rat model with PH and RVHF is among the most commonly used in cardiovascular research to explore new treatments.1-3) However, currently available techniques, particularly for quantitative evaluation of the right heart in small animal models, are very limited.In recent years, not only conventional echocardiographic imaging but also new imaging has become widely used even in RV evaluation. In particular, two-dimensional speckle tracking echocardiography (STE) has been reported to be a promising technique that quantifies myocardial deformation by tracking the ultrasonographic speckle patterns throughout the cardiac cycle in the clinical setting. 4,5) However, in past animal experiments, STE has been used to evaluate left ventricular function but rarely to evaluate RV function. 6,7) To date, the usefulness of STE for RV evaluation in small animal models has not yet been clarified. The present study was designed to validate and compare the use of STE and conventional echocardiographic variables for evaluating RV functions in a rat model with RVHF.

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“…RV myocardial performance index, which is also called Tei Index, has been proved to be more effective for analysis of global RV dysfunction than systolic and diastolic measures alone. 29) In our study, we found that RVF rats had prolonged MPI of right ventricles compared with normal controls. Besides, the geometry changes of RV also occurred, which was described by RV area and RVAW.…”

Pterostilbene reduces oxidative stress, prevents hypertrophy and preserves systolic function of right ventricle in cor pulmonale model

“…In cor pulmonale , increased oxidative stress is correlated with a decrease in right ventricular function, which is considered to be the main determinant of functional capacity and survival of patients (van de Veerdonk et al ., ). In this study, RV dysfunction was confirmed using classical echocardiographic parameters of diastolic function (E/A ratio) and systolic function (FEC, FAC and TAPSE) (Rudski et al ., ; Kimura et al ., ). FAC expresses the percentage variation in the RV area between diastole and final systole, with values below 35% indicating systolic dysfunction (Rudski et al ., ).…”

Role of Right Ventricular Dysfunction and Diabetes Mellitus in N-terminal pro-B-type Natriuretic Peptide Response of Patients With Severe Mitral Regurgitation and Heart Failure After MitraClip

“…[34][35][36] Among the several measurement parameters of RV function, TAPSE has been more extensively studied 34,35,37) because it is easily obtainable and reproducible. Previously, we reported that TAPSE < 15 mm was independently associated with adverse clinical outcomes after MC.…”