Background: Right atrial pressure (RAP) is commonly estimated using inferior vena cava (IVC) diameter and its respirophasic variations. Although a guideline has been provided for estimation of RAP due to variation in IVC dimensions based on studies in Western subjects, echocardiographic values in Asian subjects are unknown. Methods and Results:We studied 369 patients who underwent IVC ultrasound within 24 h of right heart catheterization (RHC). The maximum and minimum IVC diameter during a respiratory cycle and the percent collapse after a sniff test were measured. These IVC parameters were compared with mean RAP measured on RHC. Receiver operating characteristic curves were generated for each IVC parameter to determine the optimal cut-off to detect RAP >10 mmHg. The IVC maximum diameter cut-off for detecting RAP >10 mmHg was 19 mm (sensitivity, 75%; specificity, 78%) and the percent collapse cut-off was 30% (sensitivity, 75%; specificity, 83%). Both cut-offs were smaller than those previously reported in patients from Western countries. When the cut-off values from the existing guideline were applied to the present cohort, the sensitivity and specificity for normal RAP (0-5 mmHg) were 38.6% and 74.2%, respectively, and 60.0% and 92.0% for elevated RAP (>10 mmHg). Conclusions:The optimal IVC maximum diameter and percent collapse cut-offs to detect elevated RAP were smaller in Asian subjects than in a previously reported Western cohort. (Circ J 2014; 78: 962 -966)

FAC may provide better prognostic information than TAPSE or S' in advanced heart failure patients with DCM.

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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Association of Echocardiography. 3,4 However, in the clinical setting, sometimes the invasive RAP and RAP estimated from IVC parameters are not concordant. As a matter of fact, despite the widespread use of the IVC approach for RAP assessment, there are no previous studies that have evaluated this technique in comparison with simultaneous invasive methods. 5-8 There is no report that has compared invasive RAP with simultaneously obtained IVC parameters in a large cohort, and only a few small studies 9-11 have been published. The numbers of subjects in those studies were merely 35, 9 71, 10 and 27. 11 Moreover, most of the previous studies that support the current guidelines are derived from US and European populations. Although the current guidelines suggest a maximal IVCD A n elevated right atrial pressure (RAP) is a major prognostic predictor of morbidity and mortality in patients with pulmonary hypertension. 1 Noninvasive assessment of RAP is used to estimate systolic pulmonary artery pressure in conjunction with the tricuspid regurgitation pressure gradient, and this assessment also plays a critical role in the management of volume control in patients with congestive heart failure. 2 Currently, estimation of RAP using ultrasound measurements of the inferior vena cava (IVC) diameter (IVCD), together with its respiratory variation, is commonly performed, because it is simple and noninvasive and recommended in the current guidelines of the American Society of Echocardiography in conjunction with the European