Measurement Of Right Ventricular Volumes Research Articles

Evolving Role of Three-Dimensional Echocardiography for Right Ventricular Volume Analysis in Pediatric Heart Disease: Literature Review and Clinical Applications

Accurate knowledge of right ventricular (RV) volumes and ejection fraction is fundamental to providing optimal care for pediatric patients with congenital and acquired heart disease, as well as pulmonary hypertension. Traditionally, these volumes have been measured using cardiac magnetic resonance because of its accuracy, reproducibility, and freedom from geometric assumptions. More recently, an increasing number of studies have described the measurement of RV volumes using three-dimensional (3D) echocardiography. In addition, volumes by 3D echocardiography have also been used for outcome research studies in congenital heart surgery. Importantly, 3D echocardiographic acquisitions can be obtained over a small number of cardiac cycles, do not require general anesthesia, and are less costly than CMR. The ease and safety of the 3D echocardiographic acquisitions allow serial studies in the same patient. Moreover, the studies can be performed in various locations, including the intensive care unit, catheterization laboratory, and general clinic. Because of these advantages, 3D echocardiography is ideal for serial evaluation of the same patient. Despite these potential advantages, 3D echocardiography has not become a standard practice in children with congenital and acquired heart conditions. In this report, the authors review the literature on the feasibility, reproducibility, and accuracy of 3D echocardiography in pediatric patients. In addition, the authors investigate the advantages and limitations of 3D echocardiography in RV quantification and offer a pathway for its potential to become a standard practice in the assessment, planning, and follow-up of congenital and acquired heart disease.

Free-Breathing and Single-Breath Hold Compressed Sensing Real-Time MRI of Right Ventricular Function in Children with Congenital Heart Disease.

(1) Purpose: to compare right ventricular (RV) functional parameters in children with surgically repaired congenital heart disease (CHD) using single/double breath hold (BH) and free-breathing (FB) real-time compressed sensing (CS) cine cardiac magnetic resonance (cMRI) with standard retrospective segmented multi breath hold (RMB) cine cMRI. (2) Methods: Twenty patients with CHD underwent BH and FB, as well as RMB cine cMRI, at 3T to obtain a stack of continuous axial images of the RV. Two radiologists independently performed qualitative analysis of the image quality (rated on a 5-point scale; 1 = non-diagnostic to 5 = excellent) and quantitative analysis of the RV volume measurements. (3) Results: The best image quality was provided by RMB (4.5; range 2-5) compared to BH (3.9; range 3-5; p = 0.04) and FB (3.6; range 3-5; p < 0.01). The RV functional parameters were comparable among BH, FB, and RMB with a difference of less than 5%. The scan times for BH (44 ± 38 s, p < 0.01) and FB (24 ± 7 s, p < 0.01) were significantly reduced compared to for RMB (261 ± 68 s). (4) Conclusions: CS-FB and CS-BH real-time cine cMRI in children with CHD provides diagnostic image quality with excellent accuracy for measuring RV function with a significantly reduced scan time compared to RMB.

Integrating Right Ventricular Pressure Waveform Analysis With Two-Point Volume Measurement for Quantification of Systolic and Diastolic Function: Experimental Validation and Clinical Application

To define in an experimental model the variance, accuracy, precision, and concordance of single-beat measures of right ventricular (RV) contractility and diastolic capacitance relative to conventional reference standards, and apply the methods to a clinical data set. A retrospective, observational analysis of recorded pressure waveforms and RV volume measurements. At a university laboratory. Archived data from previous studies of anesthetized swine and awake patients undergoing clinically-indicated right-heart catheterization. Recording of RV pressure with simultaneous measurement of RV volume by conductance (swine) or 3-dimensional (3D) echocardiography (humans) during changes in contractility and/or loading conditions. Using experimental data, single-beat measures of RV contractility quantified as end-systolic elastance, and diastolic capacitance quantified as the predicted volume at an end-diastolic pressure of 15 mmHg (V15), were compared to multi-beat, preload- variant, reference standards using correlation, Bland-Altman analysis, and 4-quadrant concordance testing. This analysis indicated that the methods were not directly interchangeable with reference standards, but were sufficiently robust to suggest potential clinical utility. Clinical application supported this potential by demonstrating enhanced assessment of the response to inhaled nitric oxide in patients undergoing diagnostic right-heart catheterization. Study results supported the possibility of integrating automated RV pressure analysis with RV volume measured by 3D echocardiography to create a comprehensive assessment of RV systolic and diastolic function at the bedside.

Association of Digoxin With Preserved Echocardiographic Indices in the Interstage Period: A Possible Mechanism to Explain Improved Survival?

BackgroundFor patients with hypoplastic left heart syndrome, digoxin has been associated with reduced interstage mortality after the Norwood operation, but the mechanism of this benefit remains unclear. Preservation of right ventricular (RV) echocardiographic indices has been associated with better outcomes in hypoplastic left heart syndrome. Therefore, we sought to determine whether digoxin use is associated with preservation of the RV indices in the interstage period.Methods and ResultsWe conducted a retrospective cohort study of prospectively collected data using the public use data set from the Pediatric Heart Network Single Ventricle Reconstruction trial, conducted in 15 North American centers between 2005 and 2008. We included all patients who survived the interstage period and had echocardiographic data post‐Norwood and pre‐Glenn operations. We used multivariable linear regression to compare changes in RV parameters, adjusting for relevant covariates. Of 289 patients, 94 received digoxin at discharge post‐Norwood. There were no significant differences in baseline clinical characteristics or post‐Norwood echocardiographic RV indices (RV end‐diastolic volume indexed, RV end‐systolic volume indexed, ejection fraction) in the digoxin versus no‐digoxin groups. At the end of the interstage period and after adjustment for relevant covariates, patients on digoxin had better preserved RV indices compared with those not on digoxin for the ΔRV end‐diastolic volume (11 versus 15 mL, P=0.026) and the ΔRV end‐systolic volume (6 versus 9 mL, P=0.009) with the indexed ΔRV end‐systolic volume (11 versus 20 mL/BSA1.3, P=0.034). The change in the RV ejection fraction during the interstage period between the 2 groups did not meet statistical significance (−2 versus −5, P=0.056); however, the trend continued to be favorable for the digoxin group.ConclusionsDigoxin use during the interstage period is associated with better preservation of the RV volume and tricuspid valve measurements leading to less adverse remodeling of the single ventricle. These findings suggest a possible mechanism of action explaining digoxin’s survival benefit during the interstage period.

Unsupervised Domain Adaptation From Axial to Short-Axis Multi-Slice Cardiac MR Images by Incorporating Pretrained Task Networks.

Anisotropic multi-slice Cardiac Magnetic Resonance (CMR) Images are conventionally acquired in patient-specific short-axis (SAX) orientation. In specific cardiovascular diseases that affect right ventricular (RV) morphology, acquisitions in standard axial (AX) orientation are preferred by some investigators, due to potential superiority in RV volume measurement for treatment planning. Unfortunately, due to the rare occurrence of these diseases, data in this domain is scarce. Recent research in deep learning-based methods mainly focused on SAX CMR images and they had proven to be very successful. In this work, we show that there is a considerable domain shift between AX and SAX images, and therefore, direct application of existing models yield sub-optimal results on AX samples. We propose a novel unsupervised domain adaptation approach, which uses task-related probabilities in an attention mechanism. Beyond that, cycle consistency is imposed on the learned patient-individual 3D rigid transformation to improve stability when automatically re-sampling the AX images to SAX orientations. The network was trained on 122 registered 3D AX-SAX CMR volume pairs from a multi-centric patient cohort. A mean 3D Dice of 0.86 ± 0.06 for the left ventricle, 0.65 ± 0.08 for the myocardium, and 0.77 ± 0.10 for the right ventricle could be achieved. This is an improvement of 25% in Dice for RV in comparison to direct application on axial slices. To conclude, our pre-trained task module has neither seen CMR images nor labels from the target domain, but is able to segment them after the domain gap is reduced. Code: https://github.com/Cardio-AI/3d-mri-domain-adaptation.

Comprehensive Assessment of Right Ventricular Function by Three-Dimensional Speckle-Tracking Echocardiography: Comparisons with Cardiac Magnetic Resonance Imaging

Three-dimensional speckle-tracking echocardiography (3D-STE) has been increasingly used to quantify right ventricular (RV) function. However, direct comparisons of 3D-STE with cardiac magnetic resonance (CMR) imaging for evaluation of RV function are limited. This study aimed to test the feasibility and accuracy of 3D-STE for the quantification of RV volumes, ejection fraction (EF), and longitudinal strain in comparison with CMR imaging and to determine whether 3D-STE for RV strain is superior to two-dimensional (2D) STE in comparison with CMR imaging. A total of 195 consecutive patients referred for both CMR imaging and echocardiography were studied. Right ventricular end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RVEF, and 3D RV longitudinal strain (3D-RVLS) of the free wall by 3D-STE and 2D-RVLS of the free wall by 2D-STE, were compared with CMR measurements. Pearson correlation and Bland-Altman analyses were used to assess the intertechnique agreement. Right ventricular 3D-STE was feasible in 174 patients (89%). Right ventricular volumes and EF determined by 3D-STE strongly correlated with CMR values (RVEDV, r=0.94; RVESV, r=0.96; RVEF, r=0.91; all P<.001). Three-dimensional STE slightly underestimated the RV volumes and longitudinal strain and overestimated the RVEF. The 3D-RVLS values correlated better than 2D-RVLS values with CMR values (0.85 vs 0.64, P<.001) with smaller bias and narrower limits of agreement (bias: 2.0 and 2.6; limits of agreement: 8.5 and 12.5, respectively). The bias and limits of agreement for 3D-STE-obtained RVLS were increased in patients with RV dilation, RVEF < 45%, or lower frame rate compared with those with normal RV size, RVEF ≥ 45%, or higher frame rate, respectively. Right ventricular 3D-STE measurements were highly reproducible. The 3D-STE measurements of RV volumes, EF, and longitudinal strain are highly feasible and reproducible, and data measured by 3D-STE correlate strongly with those determined using CMR imaging. Thus, 3D-STE may be a valid alternative to CMR imaging for the quantification of RV function in everyday clinical practice.

Right ventricular three-dimensional echocardiography: the current status and future perspectives.

This review focused on right ventricular (RV) three-dimensional echocardiography (3DE) and discussed the following agenda. First, we summarized the clinical RV anatomy and function-related RV3DE use followed by the explanations about 3DSTE image acquisition, including pitfall. Next, we reviewed the reliability and feasibility of RV volume and RV ejection fraction measurements during the last decade. Besides, we described the techniques that might overcome the dropout images at RV anterior and out tract including the current limitations. Finally, speckle tracking echocardiography by RV3DE and novel RV shape assessment were reviewed. This review will help you get comprehensive information on the current status and future perspectives of RV3DE.

Early Detection and Prediction of Anthracycline-Induced Right Ventricular Cardiotoxicity by 3-Dimensional Echocardiography

ObjectivesThe purpose of this study was to assess the associations between 3-dimensional echocardiography (3DE)-derived changes in right ventricular (RV) volumes and strains with subsequent RV cardiotoxicity in patients treated with anthracyclines. BackgroundAlthough early detection and prediction of left ventricular (LV) dysfunction has been widely studied in patients receiving anthracyclines, little is known about the early changes in RV size and function in this population. MethodsA total of 74 patients with diffuse large B-cell lymphoma who received 6 cycles of anthracycline-based treatment were enrolled. Echocardiography was performed at baseline or before chemotherapy (pre-chemotherapy) (T0); after 2 cycles (T1); after 4 cycles (T2); and at the end of 6 cycles of chemotherapy (T3). Right ventricular end-diastolic volume (RVEDV), end-systolic volume (RVESV), ejection fraction (RVEF), longitudinal free wall strain (RVLFS), and longitudinal septal strain (RVLSS) were quantified by 3DE. RV cardiotoxicity was defined as a relative reduction of >10% in 3D RVEF or a relative reduction of >5% to a value of <45%. Volume status was assessed by inferior vena cava diameter (IVCD) and the estimated right atrial pressure (RAP). ResultsTwenty-seven patients developed cardiotoxicity after 6 cycles of chemotherapy (T3). Compared to baseline, increases in 3D RVEDV (58.5 ± 7.7 ml vs. 64.2 ± 7.0 ml; p < 0.001) and RVESV (27.8 ± 4.2 ml vs. 31.3 ± 4.2 ml; p < 0.001) were observed by the end of the fourth cycle of chemotherapy (T2). 3D RVLFS (−27.3 ± 3.1% vs. −24.2 ± 2.6%; p < 0.001) was also decreased at T2 compared to baseline. Statistically significant declines in 3D RVLSS (−26.1 ± 2.5% vs. −22.9 ± 2.7%; p < 0.001) and RVEF (54.0 ± 2.8% vs. 49.8 ± 2.4%; p < 0.001) were only observed at T3. A relative decrease in RVLFS of >12.4% (sensitivity, 78.6%; specificity, 82.6%; area under the curve (AUC), 0.80; p ＜ 0.001); and a relative increase in RVESV of >13.2% (sensitivity, 71.4%; specificity, 71.7%; AUC, 0.76; p ＜0.001) from baseline to T2 predicted subsequent RV cardiotoxicity at T3. IVCD and RAP did not change significantly over time. Conclusions3DE-derived measurements of RV strain and volume were associated with subsequent changes in RVEF. With further study, RVLFS and RVESV could potentially be used to predict subsequent declines in RVEF with anthracyclines.

Cardiac CT for Measurement of Right Ventricular Volume and Function in Comparison with Cardiac MRI: A Meta-Analysis.

We performed a meta-analysis to evaluate the agreement of cardiac computed tomography (CT) with cardiac magnetic resonance imaging (CMRI) in the assessment of right ventricle (RV) volume and functional parameters. PubMed, EMBASE, and Cochrane library were systematically searched for studies that compared CT with CMRI as the reference standard for measurement of the following RV parameters: end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), or ejection fraction (EF). Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and correlation coefficient (r) between CT and CMRI. Heterogeneity was also assessed. Subgroup analyses were performed based on the probable factors affecting measurement of RV volume: CT contrast protocol, number of CT slices, CT reconstruction interval, CT volumetry, and segmentation methods. A total of 766 patients from 20 studies were included. Pooled bias and LOA were 3.1 mL (-5.7 to 11.8 mL), 3.6 mL (-4.0 to 11.2 mL), -0.4 mL (5.7 to 5.0 mL), and -1.8% (-5.7 to 2.2%) for EDV, ESV, SV, and EF, respectively. Pooled correlation coefficients were very strong for the RV parameters (r = 0.87-0.93). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, an RV-dedicated contrast protocol, ≥ 64 CT slices, CT volumetry with the Simpson's method, and inclusion of the papillary muscle and trabeculation had a lower pooled bias and narrower LOA. Cardiac CT accurately measures RV volume and function, with an acceptable range of bias and LOA and strong correlation with CMRI findings. The RV-dedicated CT contrast protocol, ≥ 64 CT slices, and use of the same CT volumetry method as CMRI can improve agreement with CMRI.

Levels of agreement between cardiac magnetic resonance and conductance catheter measurements of right ventricular volumes after pulmonary artery banding.

Pressure-volume analysis is the gold standard for quantifying pump function of the right ventricle (RV); however, volume measurements based on a conductive catheter may be imprecise. The reference method for volume assessment is cardiac magnetic resonance (CMR). To determine the levels of agreement between RV volume measurements obtained by cine CMR, phase-contrast CMR (PC CMR), and a conductance catheter in an animal model. CMR was performed in 20 sheep three months after pulmonary artery banding. Ejection fraction (EF), end-diastolic (EDV), end-systolic (ESV), and stroke volumes (SV) were obtained by cine CMR and conductance catheter. Statistically significant differences between cine CMR and conductance catheter derived volume measurements were found for EDV (P < 0.001), ESV (P < 0.05), and SV (P < 0.05). Bland-Altman analysis showed very poor agreement between the two methods: EDV, bias 36.27 mL, agreement of limits 1.96-70.57 mL; ESV, bias 15.33 mL, agreement of limits -6.89-37.55 mL; and SV, bias 20.69 mL, agreement of limits 8.01-49.10 mL. Good agreement was found for SV between cine CMR and PC CMR (bias -7.0 mL, agreement of limits -24.01-9.98 mL), while SV derived from PC CMR measurements showed poor agreement with conductance catheter (bias 27.76 mL, agreement of limits -3.84-59.26 mL). Poor agreement between the conductance catheter and CMR RV volume measurements was found. PC CMR and cine CMR measurements of SV agreed well.

Integrated use of cardiac MRI and the CardioMEMS™ HF system in PAH: the utility of coincident pressure and volume in RV failure-the NHLBI-VITA trial.

This study aims to study the feasibility and safety of measuring volumetric and pressure parameters noninvasively using simultaneous cardiovascular magnetic resonance (cMR) volumetric data and time-resolved pressure waveforms from previously implanted CardioMEMS devices in pulmonary arterial hypertension (PAH) patients. Opportunities to intervene during clinically occult phases in PAH promise to herald a key transformation in our current practice for treating this complex population. Currently, it is possible and convenient to monitor daily pulmonary arterial (PA) pressures in PAH patients using the CardioMEMS device to determine clinically silent progression. Supplementation of these pressures with other prognostic measurements of right ventricular (RV) contractility, PA resistance and RV/PA coupling could add further predictive capabilities. PAH patients (n=17) with New York Hospital Association (NYHA) class III or IV heart failure (HF) and recent HF related hospitalizations were implanted with the CardioMEMS device as part of a NHLBI sponsored Trial. Implanted patients were then assessed using cMR imaging of the right ventricle (RV) along with measurement of pulmonary artery flow. Patients were imaged at one-month post implant (baseline) and at 4-month follow-up time (n=12). At baseline, patients were studied at rest and then under three different physiologic conditions: inhaled nitric oxide (INO), dobutamine (Dob) stress and volumetric stress (Vol), using a multiple slice short-axis imaging and a rapid imaging protocol. All patients were safely imaged, with no artifacts obscuring the cMR images. RV volumes were measured successfully at rest and under each stress condition using a reduced scan approach that required calibration for each patient which achieved a correlation r2 of 0.98. Variables measured included the maximal pulmonary artery elastance (Ea), maximal RV myocardial elastance (Emax) and ventricular-vascular coupling ratio (VVC). The response to stressors was determined on a patient basis. No complications occurred during the cMRI examination. It is safe and feasible to perform cMR imaging with simultaneous pulmonary artery pressure readings from the CardioMEMS device. A reduced scan approach was developed to allowed measurement of RV volumes during stress conditions. Volumetric and pressure measurements can be combined to assess fundamental myocardial properties (e.g., Emax, Ea and VVC) in PAH patients serially over time. In the future, these parameters can be tested as serial predictors of outcome and response to therapies in PAH.

Use of Tricuspid Annular Plane Systolic Excursion/Pulmonary Artery Systolic Pressure As a Non-Invasive Method to Assess Right Ventricular-PA Coupling in Patients With Pulmonary Hypertension

Use of Tricuspid Annular Plane Systolic Excursion/Pulmonary Artery Systolic Pressure As a Non-Invasive Method to Assess Right Ventricular-PA Coupling in Patients With Pulmonary Hypertension

Machine Learning–Based Three-Dimensional Echocardiographic Quantification of Right Ventricular Size and Function: Validation Against Cardiac Magnetic Resonance

Three-dimensional echocardiography (3DE) allows accurate and reproducible measurements of right ventricular (RV) size and function. However, widespread implementation of 3DE in routine clinical practice is limited because the existing software packages are relatively time-consuming and skill demanding. The aim of this study was to test the accuracy and reproducibility of new machine learning- (ML-) based, fully automated software for three-dimensional quantification of RV size and function. Fifty-six unselected patients with a wide range of RV size and function and image quality, referred for clinically indicated cardiac magnetic resonance (CMR) imaging, underwent a transthoracic 3DE exam on the same day. End-systolic and end-diastolic RV volumes (ESV, EDV) and ejection fraction (EF) were measured using the ML-based algorithm and compared with CMR reference values using Bland-Altman and linear regression analyses. RV function quantification by echocardiography was feasible in all patients. The automatic approach was accurate in 32% patients with analysis time of 15±1seconds and 100% reproducible. Endocardial contour editing was necessary after the automated postprocessing in the remaining 68% patients, prolonging analysis time to 114±71seconds. With these minimal adjustments, RV volumes and EF measurements were accurate in comparison with CMR reference (biases: EDV, -25.6±21.1mL; ESV, -7.4±16mL; EF, -3.3%±5.2%) and showed excellent reproducibility reflected by coefficients of variation <7% and intraclass correlations ≥0.95 for all measurements. The new ML-based 3DE algorithm provided accurate and completely reproducible RV volume and EF measurements in one-third of unselected patients without any boundary editing. In the remaining patients, quick minimal editing resulted in reasonably accurate measurements with excellent reproducibility. This approach provides a promising solution for fast three-dimensional quantification of RV size and function.

Three-Dimensional Echocardiography for the Assessment of Right Ventriculo-Arterial Coupling

The analysis of right ventriculo-arterial coupling (RVAC) from pressure-volume loops is not routinely performed. RVAC may be approached by the combination of right heart catheterization (RHC) pressure data and cardiac magnetic resonance (CMR)-derived right ventricular (RV) volumetric data. RV pressure and volume measurements by Doppler and three-dimensional echocardiography (3DE) allows another way to approach RVAC. Ninety patients suspected of having pulmonary hypertension underwent RHC, 3DE, and CMR (RHC mean pulmonary artery pressure [mPAP] 37.9±11.3mm Hg; range, 15-66mm Hg). Three-dimensional (3D) echocardiography was performed in 30 normal patients (echocardiographic mPAP 18.4±3.1mm Hg). Pulmonary artery (PA) effective elastance (Ea), RV maximal end-systolic elastance (Emax), and RVAC (PAEa/RV Emax) were calculated from RHC combined with CMR and from 3DE using simplified formulas including mPAP, stroke volume, and end-systolic volume. Three-dimensional echocardiographic and RHC-CMR measures for PA Ea (3DE, 1.27±0.94; RHC-CMR, 0.71±0.52; r=0.806, P<.001), RV Emax (3DE, 0.72±0.37; RHC-CMR, 0.38±0.19; r=0.798, P<.001), and RVAC (3DE, 2.01±1.28; RHC-CMR, 2.32±1.77; r=0.826, P<.001) were well correlated despite a systematic overestimation of 3DE elastance parameters. Among the whole population, 3D echocardiographic PA Ea and 3D echocardiographic RVAC but not 3D echocardiographic RV Emax were significantly lower in patients with mPAP < 25mm Hg (n=41) than in others (n=79). Among the 90 patients who underwent RHC, 3D echocardiographic PA Ea and 3D echocardiographic RVAC but not 3D echocardiographic RV Emax increased significantly with increasing levels of pulmonary vascular resistance. Three-dimensional echocardiography-derived PA Ea, RV Emax, and RVAC correlated well with the reference RHC-CMR measurements. Ea and RVAC but not Emax were significantly different between patients with different levels of afterload, suggesting failure of the right ventricle to maintain coupling in severe pulmonary hypertension.

Pulmonary hypertension due to left heart disease: diagnostic and prognostic value of CT in chronic systolic heart failure.

To evaluate the ability of chest computed tomography (CT) to predict pulmonary hypertension (PH) and outcome in chronic heart failure with reduced ejection fraction (HFrEF). We reviewed 119 consecutive patients with HFrEF by CT, transthoracic echocardiography (TTE) and right heart catheterization (RHC). CT-derived pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio), left atrial, right atrial, right ventricular (RV) and left ventricular volumes were correlated with RHC mean pulmonary arterial pressure (mPAP) . Diagnostic accuracy to predict PH and ability to predict primary composite endpoint of all-cause mortality and HF events were evaluated. RV volume was significantly higher in 81 patients with PH compared to 38 patients without PH (133 ml/m2 vs. 79 ml/m2, p < 0.001) and was moderately correlated with mPAP (r=0.55, p < 0.001). Also, RV volume had higher ability to predict PH (area under the curve: 0.88) than PA diameter (0.79), PA:A ratio (0.76) by CT and tricuspid regurgitation gradient (0.83) and RV basal diameter by TTE (0.84, all p < 0.001). During the follow-up period (median: 3.4 years), 51 patients (43%) had HF events or died. After correction for important clinical, TTE and RHC parameters, RV volume (adjusted hazard ratio [HR]: 1.71, 95% CI 1.31-2.23, p < 0.001) and PA diameter (HR: 1.61, 95% CI 1.18-2.22, p = 0.003) were independent predictors of the primary endpoint. In patients with HFrEF, measurement of RV volume and PA diameter on ungated CT are non-invasive markers of PH and may help to predict the patient outcome. • Right ventricular (RV) volume measured by chest CT has good ability to identify pulmonary hypertension (PH) in patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF). • The accuracy of pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio) to predict PH was similar to previous studies, however, with lower cut-offs (28.1 mm and 0.92, respectively). • Chest CT-derived PA diameter and RV volume independently predict all-cause mortality and HF events and improve outcome prediction in patients with advanced HFrEF.

Echocardiographic assessment of right ventricular systolic function

Assessment of right chamber function has become increasingly popular and important in recent decades, complementing the evaluation of left chamber functional parameters. The late adoption and integration of right ventricular (RV) function into a complete evaluation of cardiac function could be due in part to the difficulty in visualization of the whole right ventricle, inconsistency in the analysis of RV parameters, and poor understanding of the impact of RV function on prognosis. From M-mode to 2-dimensional (2D) measurements of RV size and function, there have been arrays of parameters that provide important information of the right ventricle. However, there are limitations of using 2D echocardiography to quantify RV volume and ejection fraction (EF), and currently accurate measurements of RV volumes and EF can be obtained using cardiac magnetic resonance (CMR) imaging. Using 3-dimensional echocardiography (3DE), the measurements of RV volumes and EF have become feasible and reproducible. Importantly, 3D measurements have been validated against CMR with higher correlation compared to 2D measurements. With the establishment of reference values, 3D echocardiography determined RV volumes and EF have the potential for better understanding of RV function and exploration of its significance for outcome research in various clinical scenarios.

Knowledge-based reconstruction for measurement of right ventricular volumes on cardiovascular magnetic resonance images in a mixed population.

Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital heart disease with conventional analysis.

Is Echocardiographic Assessment Right Ventricular Function Routinely Performed?

Assessment of right chamber function has become increasingly popular and important in recent decades, complementing the evaluation of left chamber functional parameters. The late adoption and integration of right ventricular (RV) function into a complete evaluation of cardiac function could be due in part to the difficulty in visualization of the whole right ventricle, inconsistency in the analysis of RV parameters, and poor understanding of the impact of RV function to prognosis. From M-mode to 2-dimensional (2D) measurements of RV size and function, several parameters, such as fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and RV free wall strain assessed by 2D speckle tracking echocardiography provide important information of the right ventricle. However, there are limitations of using 2D echocardiography to quantify RV volume and ejection fraction (EF), and currently accurate measurements of RV volumes and EF can be relied on cardiac magnetic resonance (CMR) imaging. CMR derived RVEF has been reported to provide incremental prognostic value over left ventricular ejection fraction in patients with idiopathic and ischemic dilated cardiomyopathy. With use of 3-dimensional (3D) echocardiography in conjunction with updated version of RV quantification software, the measurements of RV volumes and EF have become feasible and reproducible. It accuracy has been validated against CMR. With the establishment of reference values in the recent publications, 3D echocardiography determined RV volumes and EF have the potential for our better understanding of RV function and exploration of its significance for outcome research in various clinical scenarios. Thus, it is a prime time to assess RV function with 2D and preferentially 3D echocardiography in routine echocardiography examinations.

0241: Knowledge-based 3D reconstruction compared to MRI for evaluation of right ventricular volumes and function in congenital heart diseases affecting the right ventricle

Right ventricular (RV) volume and ejection fraction (RVEF) measurements are essential in the management of children with congenital heart disease. Cardiac Magnetic resonance imaging (MRI) is considered the reference method for RV volumes and RVEF measurements. Three-dimensional knowledge-based reconstruction (3D-KR) derived from two-dimensional echocardiographic imaging is a novel technique. The aim of this study was to assess the feasibility and reliability of this technique in children with diverse CHD involving the right ventricle. 103 children (range age 0,1 to 18 years) referred for cardiac MRI, were included. Among them, 33 patients had barometric overload, 40 patients had volumetric overload, 18 patients had mixed overload, and 12 had Fontan circulation. Echocardiographic image acquisition was performed using a standard ultrasound probe linked to a Ventripoint Medical Systems unit. Parameters analysed were end-diastolic volume (EDV), end-systolic volume (ESV), and RVEF. The method of disk was used for CMR RV volumes. Intra-observer, inter-observer, and inter-technique variability was assessed using coefficients of variation (COV), and Bland-Altman analysis. Feasibility of 3D-KR was 100%. Echocardiographic RV volumes correlated well with CMR (EDV, CC=0.96; ESV, ICC=0.93; RVEF, ICC=0.75). For inter-observer analyses, COV were 8% for EDV, 15% for ESV, and 17% for EF. For intra-observer analyses, COV were 4% for EDV, 7% for ESV, and 9% for EF. The correlation of volumes and RVEF with MRI was slightly worse in the group with mixed overload compared with patients with volumetric or barometric overload. 3D-RVEF was overestimated compared with MRI whereas the volumes tend to be underestimated. 3D-KR is feasible in children. It provides accurate and reproducible measurements of RV volumes. This new technique can be used as an accurate routine tool to assess RV function in CHD with pure barometric or volumetric overload. Abstract 0241 - Figure: RV-EDV Right Ventricular End Diastolic Volume

ACCURACY AND REPRODUCIBILITY OF RV VOLUMES MEASUREMENTS BY CMR USING SHORT AXIS VS LONG AXIS FOUR CHAMBER VIEWS IN PATIENTS AND RV PHANTOMS

Cardiac magnetic resonance (CMR) is the reference standard for right ventricular (RV) volume and function assessment. A stack of short-axis slices (SAX) is routinely used to measure RV volumes but basal slice selection is challenging due to tricuspid annular plane excursion. Long-axis views offer a clearer view of the tricuspid and pulmonary valve planes, eliminating the need for cross-referencing; yet, there is significant partial-volume variability due to large areas of tangential subendocardial borders not perpendicular to the plane. We assessed inter-reader agreement between two CMR Methods for measurement of RV volumes in patients. We also assessed agreement between CMR derived RV volumes and physical volume measurement obtained from explanted animal hearts. The study was conducted in both patients undergoing a clinically indicated scan (n=50), and in explanted pig hearts (n=10). The RV of explanted pig heart was injected with a plastic mold (Reprosil) and its reference volume was measured using water displacement. For patients and molds, the RV was imaged with a full stack of slices covering the heart in SAX and in 4-chamber long axis view (4ch). RV volumes were traced, from both imaging planes, by 2 readers for the patient data and 2-4 readers for the explant data. Inter-reader agreement of the RV volumes was assessed for SAX and 4ch using concordance correlation coefficients and Bland-Altman limits of agreement. For patients, SAX and 4ch had excellent inter-reader agreement with SAX having a slightly higher coefficient (Table). For explants, the inter-reader agreement was poor in comparison to patient data, with 4ch being the most reproducible method. When comparing CMR derived volumes to the reference volume of the molds, SAX views had the smallest limits of agreement, closely followed by 4ch. However both SAX and 4ch views overestimated the volume by about 4ml (Image). SAX is the most widely used and most accurate imaging plane for measurements of RV volumes, while inter-reader agreement is excellent for both SAX and 4ch. Both SAX and 4ch mildly overestimate RV volumes. The different morphology of the porcine heart and the challenges of tracing a still image may explain the poor inter-reader agreement for measuring the volume of explanted RV molds.View Large Image Figure ViewerDownload (PPT)