Right Ventricular Dilatation Research Articles

Abstract 4136169: Phenotypic clustering of right heart dilatation in pulmonary arterial hypertension

Introduction: Right ventricular (RV) and right atrial (RA) dilatation are important hallmarks of disease severity in patients with pulmonary arterial hypertension (PAH). To obtain more insights on the clinical significance of RA dilatation, we phenotypically characterized patients with right heart dilatation. Aim: Description of different RV/RA phenotypes in PAH Methods: 203 incident, treatment naïve PAH patients with cardiac magnetic resonance (CMR) imaging were included. Phenotypic clustering was based on RA and RV dilatation. Conform literature, RA dilatation was defined by a RA index maximal area >15 cm 2 /m 2 . RV dilatation was defined by an RVEDV/LVEDV ratio >1.3 and >2.4 for extreme dilatation. Results: Four phenotypic patient clusters were identified: no dilatation (n=48), RV dilatation (n=78), RV+RA dilatation (n=53) and extreme RV dilatation + RA dilatation (n=23), Figure 1A. To unravel the additive clinical value of RA dilatation, we mainly compared patients with RV dilatation and patients with RV+RA dilatation. Intriguingly, patients with RV+RA dilatation demonstrated lower 3- and 5-year survival rates (58% and 43% vs. 75% and 55%) (Figure 1B) and were less likely to reverse RV dilatation after treatment initiation than patients with RV dilatation only. Despite the consequences of RA dilatation, we could not identify an explanation for the difference in RA dilatation between both groups. No difference in afterload was observed, shown by comparable pulmonary vascular resistance (9.9 [6.8-13] WU vs. 10 [7.5-12.3] WU, p>0.05). RV function was similarly impaired (RV ejection fraction: 36±9% vs. 33±9%, p>0.05). End-diastolic elastance (0.73 [0.39-1.11] mmHg/mL vs. 0.58 [0.40-0.94] mmHg/mL, p>0.05) and severity of tricuspid regurgitation did not differ. Finally, diuretic use (40% vs. 40%, p>0.05), age (54±16 vs. 57±19 yrs, p>0.05), female gender (70% vs. 60%, p>0.05) and iPAH diagnoses was similar (69% vs. 59%, p>0.05). Conclusion: PAH-patients with both RA and RV dilatation have a worse clinical profile than patients with only RV dilatation. However, no clear trigger for RA dilatation was found and future mechanistic studies should unravel factors explaining these differences in right heart adaptation.

Abstract 4136316: BMP10 as novel marker for right atrial dilatation and pressure in precapillary pulmonary hypertension

Introduction: Precapillary pulmonary hypertension (precPH) leads to increased right atrial (RA) stretch and pressure. The right atrium is the major source of bone morphogenetic protein 10 (BMP10) in adults. Aim: This study aims to investigate BMP10 in relation to RA dilatation and pressure overload. Methods: We studied BMP10 mRNA in fresh RA tissue of N=5 Chronic Thromboembolic Pulmonary Hypertension (CTEPH) patients and N=9 controls and protein expression in paraffin-embedded RA tissue of N=4 Pulmonary Arterial Hypertension (PAH) patients and N=6 controls. We prospectively included 48 precPH patients (N=22 idiopathic PAH, N=14 hereditary PAH and N=12 CTEPH, and N=16 controls. To study BMP10-induced transcriptional activity, we assayed serum samples in human microvascular endothelial cells (HMEC) with a BMP-responsive transcriptional luciferase assay. BMP10 activity was calculated by subtracting BMP activity after incubation with antibodies for Alk1Fc and bone morphogenetic protein 9 (BMP9). We assessed correlations between BMP10 activity and RA dilatation (RA max volume>79 ml/m 2 for male or >69 ml/m 2 for female) and right ventricular (RV) dilatation (RV end-diastolic volume>108 ml/m 2 for male and >96 ml/m 2 for female). In a cohort of CTEPH patients that underwent pulmonary endarterectomy (PEA) we assessed the effect of pressure unloading on BMP10 activity. Normality of data was checked and statistical differences between groups were tested using an independent sample t-test or Wilcoxon rank-sum test. Results: BMP10 mRNA, protein and downstream activity were higher in the precPH RA tissue (Figure 1A-F). High systemic BMP10 activity was associated with RA dilatation and high RA pressure, but not RV dilatation in precPH (Figure 2A-C). Finally, pressure unloading after PEA in CTEPH patients results in a reduction in BMP10 activity (figure 2D). Conclusions: Local RA BMP10 expression and activity is increased in precPH. Increased systemic BMP10 activity was related to RA dilatation and pressure. Pressure unloading of the right heart leads to a reduction of systemic BMP10 activity. Future studies are needed to determine whether increased BMP10 release is an adaptative mechanism or can be used as therapeutic target.

Abstract 4114497: Shape Variations in Right Ventricular 3D Geometry are associated with adverse outcomes in Hypoplastic Left Heart Syndrome Patients: A Fontan Outcomes Registry using CMR Examination (FORCE) Study

Introduction: Right ventricular (RV) function is critical to the long-term health of patients with hypoplastic left heart syndrome (HLHS). However, conventional measurements do not consider the range of RV morphology that may impact RV function and lead to adverse outcomes. In this study, we determined associations between RV shape and clinical outcomes of HLHS using statistical shape modeling (SSM) and a large cardiac magnetic resonance (CMR) multicenter registry. Methods: Three hundred and twenty-eight studies from unique HLHS patients in the F ontan O utcomes R egistry using C MR E xaminations (FORCE) were post-processed by a core lab at one institution, including volumetry and strain analysis. 3D end-diastolic models of RV were reconstructed using Mimics (Materialise). SSM was performed via Shapeworks Studio (NIH/NIGMS CIBC) to derive mean template and quantified shape variations (shape mode) representing deviation from the mean. RV shape relationship with mortality/heart transplant was assessed using bivariable/multivariable analyses with stepwise model selection. Results: The mean template from all 328 patients resembled a circumferentially dilated RV with loss of concavity in septal wall (Fig A). Several generalized variants were identified (Fig B), particularly p1 – a sigmoidal / “apical bulge” variant where the RV apex dilates and "wraps” around the hypoplastic left ventricle (Fig C). Twenty-eight patients (8.5%) experienced mortality/heart transplant at 2.5±2.4 years after CMR. On bivariable analysis, p1 was associated with mortality/heart transplant, along with larger indexed RV end-diastolic volume/mass and reduced global circumferential strain. On multivariable analysis, p1 and indexed RV mass were associated with mortality/heart transplant (Table). Conclusions: Statistical Shape Modeling can define the “usual” RV shape of HLHS. A sigmoidal shape variant is associated with adverse outcomes. SSM may provide patient-specific metrics to define RV dysfunction in HLHS.

Insulin-like growth factor binding protein 2 predicts course of concomitant right-ventricular dilation and tricuspid regurgitation after transcatheter edge-to-edge mitral valve repair

Abstract Aims Right ventricular (RV) dilation and secondary tricuspid regurgitation (TR) are highly prevalent comorbidities in patients with mitral regurgitation and are associated with a worse prognosis. TR improvement after successful transcatheter edge-to-edge mitral valve repair (M-TEER) is reported regularly, however specific factors contributing to the recovery of RV function and TR after M-TEER are poorly understood. Particularly the role of serum biomarkers in this context is unclear. We aimed to identify specific biomarkers associated with the course of concomitant RV dilation and TR after M-TEER. Methods and Results We prospectively included 242 patients undergoing M-TEER at our center and obtained pre-procedural blood samples for biomarker analysis. A commercial multiplex protein assay (Cardiovascular III, Olink, Uppsala, Sweden) was used to quantify expression levels of 92 defined biomarkers. We then analyzed differences in biomarker expression between patients with and without right ventricular reverse remodeling (RVRR) as defined by improvement of concomitant TR by at least one grade and/or downsizing of the basal RV diameter of at least 10%. 242 patients were included in this analysis, 94 had no/mild concomitant TR at baseline, 148 had moderate/severe TR. RV diameters correlated with TR severity and were significantly larger in patients with moderate/severe TR. At baseline, expression of numerous cardiometabolic biomarkers was significantly higher in patients with moderate/severe TR. These included NT-proBNP (1.9-fold, p < 0.001), matrix metalloproteinase 2 (1.4-fold, p < 0.001) as well as insulin-like growth factor binding proteins 1 (1.7-fold, p < 0.001), -2 (1.3-fold, p = 0.001) and -7 (1.4-fold, p < 0.001). Follow-up analysis was performed in patients with initial moderate/severe TR. The course of TR and RV dimensions three months after M-TEER could be assessed in 99 patients (56 with moderate TR, 43 with severe TR). RVRR had occurred in 50 patients (50.5%). Patients without RVRR had a higher prevalence of chronic pulmonary disease (24.5 vs. 2.2%, p < 0.001). No further differences in clinical characteristics were found. Specifically, RV diameter, systolic pulmonary artery pressure (sPAP) and right-ventricular systolic function did not differ substantially between both groups. Strikingly however, the expression of insulin-like growth factor binding protein 2 (IGFBP-2) was significantly higher in patients, who did not develop RVRR (fold change 1.3 compared to patients with RVRR, p = 0.022). After adjustment for covariates IGFBP-2 was independently associated with absence of RVRR (Odds Ratio 2.078, 95% Confidence interval 1.108 – 3.897, p = 0.023). Conclusions In patients undergoing M-TEER with concomitant moderate or severe TR, numerous cardiometabolic biomarkers including IGFBP-2 are upregulated. Higher levels of IGFBP-2 at baseline are independently associated with persistent TR and/or RV dilation after M-TEER.

Beyond 2D echocardiography: A novel multiparametric assessment of right ventricular dysfunction in transcatheter tricuspid valve repair

Abstract Background Patients with severe tricuspid regurgitation (TR) are heterogenous and complex in terms of etiology, comorbidities and state of disease. Right ventricular (RV) function measured by RV to pulmonary artery coupling (RVPAc) is prognostic in transcatheter tricuspid valve repair (T-TEER). However, traditional 2D echocardiographic measures have critical limitations and RVPAc fails to respect the degree of volume overload/dilation of the RV, which is a key clinical tracer for right ventricular dysfunction (RVD). Purpose We aimed to refine RVPAc by incorporating RV dilation, assessed by 3D echocardiography, to improve the assessment of RV dysfunction for an enhanced outcomeprediction in T-TEER patients. Methods We analyzed 262 patients undergoing T-TEER with complete 3D echocardiography. Results Despite similar RV function across groups, RV dilation (HR 1.85; 1.10, 3.12; p=0.020) and impaired RV free wall longitudinal strain (RVFWLS, HR 1.73, 1.02, 2.92, p=0.042) predicted increased 1-year mortality. A novel RVPAc parameter [RVFWLS/(3D-RVEDV*sPAPinvasive)] was developed, associating RVPA-Uncoupling with a tripled risk of death (HR 3.19, 1.7-6.0, p<0.001). NYHA Class IV and the new RVPAc were independent mortality predictors after T-TEER, with the modified RVPAc showing superior predictive value over traditional RVPAc (c-index 0.68 vs. 0.57, p=0.027). Conclusion The novel RVPAc parameter, integrating RV dilation and function, is a powerful predictor of survival post-T-TEER, underscoring the importance of timely intervention in severe TR and RVD. 3D echocardiography plays a critical role in assessing RV dimension and function, with implications for the management and prognosis of TR patients.Central Figure

Cardiac chamber three-dimensional volumes and deformation predict clinical outcomes in chronic mitral regurgitation

Abstract Background In patients with mitral regurgitation (MR), cardiac remodeling assessed by two-dimensional (2D) echocardiographic linear indexes is highly variable and not suitable for individualized risk assessment. Purpose To evaluate whether measurements of myocardial strain and left atrial (LA), left ventricular (LV) and right ventricular (RV) three-dimensional (3D) volumes improve risk assessment in MR. Methods In the prospective 3D Echocardiography and Cardiovascular Prognosis in Mitral Regurgitation study (3D-PRIME), 176 patients with significant (moderate or greater) MR were investigated with 2D/3D echocardiography. Referral criteria for mitral intervention followed current guidelines. LA remodeling was assessed by the maximum and minimum 3D LA volume (3D-LAV), peak reservoir strain (LASr), and stiffness (i.e. the ratio: mitral peak E-wave divided by the annular e’ velocity (E/e´) / LASr). LV and RV were considered dilated in case of increased 3D end-diastolic (LV>=86/74 and RV>=87/74ml/m2 in men/women) and end-systolic volumes indexed for body surface area (LV>=41/33 and RV>=44/36ml/m2 in men/women). Peak global longitudinal strain was measured in the LV (LV-GLS) and the RV free wall (RV-FWS). The primary outcome was a composite of mitral valve surgery, percutaneous mitral edge-to-edge repair and death. Results During a 14 [8-24] months follow-up, the patients (70±13 years, 39% women) experienced 73 events including 14 deaths. In univariate survival analyses, LV and RV dilatation, but not LV-GLS and RV-FWS, were associated with the primary outcome (Figure) and had superior predictive value to 2D volumes and diameters (p<0.05). On contrary, both atrial size and function predicted outcome, with 3D-LAV (HR 1.01, 95% CI 1.00-1.01), LASr (HR 1.03, 95% CI 1.01-1.06) and increased LA stiffness (Figure) all significant predictors of events (p<0.05). In multivariate Cox analysis with adjustment for age, sex, body mass index and MR etiology, dilated LV (HR 2.6, 95% CI 1.5-4.4), dilated RV (HR 2.0, 95% CI 1.1-3.6) and increased LA stiffness ((HR 2.4, 95% CI 1.3-4.6) were independently associated with higher rate of events (p<0.05). Conclusion In patients with moderate or greater MR, increased cardiac chamber 3D volumes and LA stiffness, as well as impaired LA reservoir strain are associated with higher risk of disease progression towards mitral valve intervention and death. Our findings indicate that assessment of both cardiac chamber 3D size and LA deformation can contribute to increased diagnostic and prognostic precision in patients with MR.

Long term follow up in pulmonary embolism: can right ventricular strain echocardiographic imaging contribute to refine risk stratification?

Abstract Background In pulmonary embolism (PE), the usual evaluation of early risk of death includes clinical, biological and two-dimensional right ventricular (RV) echocardiographic (TTE) parameters. Purpose We hypothesized that myocardial strain analysis could contribute to risk of death prediction at long term follow up. Methods We retrospectively analyzed 477 patients hospitalized for acute EP. Usual parameters used to define RV dysfunction were evaluated using TTE (RV dilatation, systolic pulmonary arterial pressure, TAPSE, S’, Fractionnal Area Change (FAC), end diastolic RV diameter and right atrial, RA, area). In addition, we evaluated, left ventricle (LV) longitudinal, left atrial (LA), RA and RV free wall strains. Patients without history of cancer (n=419) were analyzed on the primary outcome of death at long term follow up. Results Mean of age was 63.7 ± 17.2 years and 227 (47.6) patients were male. The main clinical and echocardiographic characteristics are displayed in the Table 1. During a mean follow-up was 45.0 ± 16.6 months, the primary outcome occurred in 56 patients. In multivariable analysis, systolic pulmonary arterial pressure, indexed right atrial and left atrial volumes, right ventricle free wall strain, right ventricle global longitudinal strain were the only predictors of death (Table 2). Conclusion Atrial volumes and RV strain appeared as strong predictors of death in PE at long term follow up. Right ventricle myocardial strain analysis should be evaluated in each patient hospitalized for PE.

Ringlike late gadolinium enhancement: prevalence, association with cardiac phenotype, and patient outcome in an unselected cohort referred for cardiovascular magnetic resonance imaging

Abstract Background The identification of a non-ischemic ringlike enhancement in the left ventricular (LV) myocardium by cardiac magnetic resonance imaging (CMR) has emerged as a significant biomarker associated with arrhythmogenic cardiomyopathy (CMP) and adverse patient outcomes. Recently, the term "scarring CMP" has been also proposed to encompass various conditions characterized by a high burden of non-ischemic, often ring-like, myocardial scarring, including both genetic and acquired etiologies. Purpose To systematically evaluate CMR phenotypic traits and etiologic backgrounds in patients with ringlike enhancement and to assess the burden of adverse outcomes during follow-up (FU). Methods This is a single-center, retrospective analysis of prospectively enrolled patients undergoing CMR (from 2002 to 2024). Ringlike late gadolinium enhancement (LGE) was defined as continuous enhancement in three or more adjacent segments based on the AHA 17 segment model. Patients records were reviewed for etiologic classification and FU assessment. Results Among 23.472 patients, 19.696 (84%) underwent LGE assessment. In 152 patients (0.77%; 73% male; mean age 48.5 ± 17 years) a ringlike LGE was identified. The mean number of LV segments with LGE was 10 ± 3. Right ventricular (RV) LGE was present in 23% of subjects. LV fatty metaplasia was detected in 22%. Infero-lateral segments were most frequently affected. CMR showed the following morpho-functional features: LV dilatation (53%), LV hypokinesia (69%), LV hypertrophy (10.5%), LV non-compaction (11%), RV dilation (26%), and RV ejection fraction < 40% (21%). Phenotypic classification according to 2023 ESC guidelines identified dilated CMP phenotype (43%), non-dilated LV CMP phenotype (39%), predominant arrhythmogenic right ventricular phenotype (6%), hypertrophic phenotype (7%). 5% of cases remained unclassified, all of them showing LV dilated non-hypokinetic phenotype. Genetic analysis was performed in 101 patients (66%). Etiologic classification revealed non-desmosomal gene related CMP (24%), desmosomal gene related CMP (8%), inflammatory CMP (16%), genetic neuromuscular diseases (5%), congenital metabolic errors (3%), familiar gene elusive CMP (2%) and unknown etiology (45%). Notably, only 17% of patients classified as having inflammatory CMP and 66% of those with unknown etiology underwent genetic testing, with negative results. The median follow-up duration was 3 (IQR: 1-7) years. All-cause mortality occurred in 10.5% of patients, while 17% experienced sustained ventricular tachycardia, appropriate implantable cardioverter-defibrillator therapies, or sudden cardiac death. Heart transplantation or left ventricular assist device implantation was required in 8% of cases. Conclusion Ringlike LGE is a rare, non-disease-specific feature that can be found in different morpho-functional CMP phenotypes. It is associated with frequent genetic-determined etiology and high burden of arrhythmic and non-arrhythmic outcomes.

Proteomic Signatures of Right Ventricular Outcomes in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a disease of progressive right ventricular (RV) failure with high morbidity and mortality. Our goal is to investigate proteomic features and pathways associated with RV-focused outcomes including mortality, RV dilation, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) in PAH. Participants in a single-institution cohort with 3 years of follow-up underwent proteomic profiling of their plasma using 7288 aptamers (targeting 6467 unique human proteins). Partial least squares discriminant analysis was performed to assess global protein variation associated with mortality, RV dilation, and NT-proBNP levels. Differentially abundant proteins and enriched pathways associated with outcomes were identified following baseline adjustments. RV vulnerability models estimated associations for individuals with similar afterload following adjustment for pulmonary vascular resistance. A total of 117 participants with PAH were included. Partial least squares discriminant analysis of the proteome showed clear separation between survivors and nonsurvivors, participants with dilated versus nondilated RVs, and across NT-proBNP levels. Proteins and pathways involving the ECM (extracellular matrix) were upregulated in participants who died during follow-up, those with severe RV dilation, and those with higher levels of NT-proBNP. Pulmonary vascular resistance adjustment reinforced the importance of ECM proteins in the association with RV vulnerability, independent of afterload. These findings were confirmed in independent PAH cohorts with available plasma proteomics and RV tissue gene and protein expression. Distinct plasma proteomic profiles are associated with mortality, RV dilation, and NT-proBNP in PAH. Proteins and pathways governing tissue remodeling are strongly associated with poor outcomes, may mediate RV vulnerability to right heart failure, and represent promising candidates as biomarkers and potential therapeutic targets.

A new electrocardiographic parameter terminal D1S + D3R predicts right ventricular dilatation in acute pulmonary embolism

Objective Right ventricular (RV) overload findings affect the risk classification and treatment approach in acute pulmonary embolism (APE). Recently, it was reported that a new electrocardiography (ECG) parameter, terminal D1S + D3R (T-D1S + D3R) pattern, supported the diagnosis of APE. We aim to search the relationship between T-D1S + D3R pattern and right ventricular dilatation (RVD) in APE. Methods This single-centre, retrospective study was designed with patients aged > 18 years. We screened 267 patients who underwent transthoracic echocardiography (TTE) because of confirmed APE in our emergency department. This study included 72 patients with RVD and 139 patients without RVD [male 41.7%, median age 73,0 (20.8) years; 49.6% male, median age 64,0 (24.0) years]. We compared T-D1S + D3R between RVD (+) and RVD (-) groups. Results We determined that RVD (+) group had more patients with the T-D1S + D3R parameter than RVD (-) group [51 (70.8%) vs. 25 (18.0%), p < 0.001]. In the univariate logistic regression analyses S1Q3T3, (in)complete right bundle branch block (RBBB), T-D1S + D3R, D3-V1 T wave inversion (TWI), V1-3/4 TWI, V1-3/4 ST-segment elevation, and frontal QRS-T [f(QRS-T)] angle predicted RVD, while T-D1S + D3R, V1-3/4 ST-segment elevation, and f(QRS-T) angle remained independent predictors of RVD in patients with APE. Conclusions T-D1S + D3R, a new ECG parameter, was an independent predictor of RVD in patients with APE.

Correlation between Epsilon Wave and Late Potentials in Arrhythmogenic Right Ventricular Cardiomyopathy-Do Late Potentials Define the Epsilon Wave?

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterised by progressive fibrosis predominantly of the right ventricular (RV) myocardium, resulting in life-threatening arrhythmias and heart failure. The diagnosis is challenging due to a wide spectrum of clinical symptoms. The important role of ECG was covered in the current diagnostic criteria. The role of the epsilon wave (EW) is still under discussion. Aim: The aim of the study was to examine a potential association between the EW and late ventricular potentials (LPs) in ARVC patients (pts). The correlation between RV dilatation or dysfunction and LPs/EW was also analysed. Methods: The ARVC group consisted of 81 pts (53 men, aged 20-78 years) fulfilling 2010 International Task Force Criteria. 12-lead ECG, LPs, Holter, and ECHO were performed in all pts. The presence of EW was analysed in ECG by 3 investigators. LPs were detected by signal-averaged ECG (SAECG). SAECG was considered positive for LPs when at least two of the three following criteria were met: (1) the filtered QRS duration (fQRS) ≥ 114 msec; (2) the duration of the final QRS fragment in which low-amplitude signals lower than 40 μV are recorded (LAS-40 > 38 msec); and (3) the root mean square amplitude of the last 40 milliseconds of the fQRS complex (RMS-40 < 20 μV). The results were compared with a reference group consisting of 53 patients with RV damage in the course of atrial septum defect (ASD) or Ebstein's Anomaly (EA). Results: In the ARVC group, a significant relationship was observed between the occurrence of EW and the presence of LPs. EW was more common in the LP+ than in the LP- patients (48.1% vs. 6.9%, p < 0001; OR 12.5; 95% CI [2.691-58.063]). In ARVC pts, RVOT > 36 mm, RVIT > 41 mm, and RV S' < 9 cm/s were observed significantly more often in the LPs+ than in the LPs- group (OR [95% CI]: 8.3 [2.9-1.5], 6.4 [2.2-19.0] and 3.6 [1.1-12.2], respectively). In the ARVC group, any of fQRS > 114 ms, LAS > 38 ms, and RMS < 20 μV were significantly more frequent in EW+ pts. In multivariate analysis, the independent factors of the EW were LAS-40 and RV S'. In the LPs- subgroup, RVOT > 36 mm was more frequent in ASD/EA than in ARVC (70.4% vs. 25%, p = 0.002). Similarly, in the LPs- subgroup, RVIT > 41 mm was encountered more frequently in ASD/EA than in ARVC (85.2% vs. 48.3%, p = 0.004). Conclusions: In ARVC, there is an association between EW and LPs, with both probably resulting from the same process of fibrofatty substitution of the RV myocardium. Although RV dilatation is common in ASD and EA, it does not correlate with LPs.

Predictors and outcomes associated with right ventricular function in patients with acute respiratory distress syndrome treated with Veno-venous extracorporeal membrane oxygenation.

Right ventricular dysfunction is associated with mortality in patients with acute respiratory distress syndrome (ARDS) but information in veno-venous extracorporeal membrane oxygenation (ECMO) settings is limited. Study objectives were to examine factors associated with right ventricular (RV) systolic dysfunction (RVSD) and RV dilation in ECMO patients with ARDS, to compare outcomes in those with and without RVSD and RV dilation defined by qualitative and quantitative parameters, and to describe RVSD evolution during ECMO. Retrospective observational study of adult ARDS patients supported with ECMO at a tertiary care hospital. Of a total of 62 patients, 56% had RVSD and 61% had RV dilation by qualitative assessment. Male gender, COVID-19, hypercarbia, and pneumothorax were associated with RVSD and RV dilation. In-hospital mortality was significantly higher in patients with RV dilation vs. no dilation (42% vs. 17%, p = .05) but comparisons for patients with and without RVSD (37% vs. 26%, respectively) did not reach statistical significance. Findings were similar when RV size and function were quantified by right to left ventricle end-diastolic area ratio and fractional area change (39% vs. 21% and 36% vs. 20% respectively; p = NS). Of 39 patients with multiple echocardiograms, 9 of 18 with initially normal RV function developed RVSD while RV function normalized in 10 of 21 patients who began ECMO with RVSD. Study results suggest an association of RV dilation and RVSD with worse outcomes and a dynamic nature of RV function necessitating close monitoring during the ECMO course.

Unlocking the power of echocardiography: strategies in risk stratification of patients with PE using echocardiography

Objectives: Pulmonary embolism (PE) is challenging to diagnose due to nonspecific symptoms. While computed tomography pulmonary angiography (CTPA) is the gold standard, transthoracic echocardiography (TTE) is frequently used first. This study aimed to evaluate the accuracy of TTE findings in predicting the severity of CTPA-confirmed PE. Methods: This retrospective study in 2023, analyzed 124 patients who underwent CTPA for suspected PE at Seyed Al Shohada Hospital of Urmia, Iran. The Pulmonary Embolism Severity Index (PESI), as a risk stratification tool for pulmonary embolism, was measured in the first hours of hospitalization. TTE was performed 48 hours following hospital admission, with an emphasis on Key TTE parameters, including McConnell’s sign, D-shape septum sign, right ventricular (RV) dimensions, left ventricular dimensions, pulmonary artery (PA) diameter, tricuspid regurgitation gradient (TRG), Tricuspid annular plane systolic excursion (TAPSE) and PA acceleration time (PaACT). Sensitivity, specificity and predictive value were all calculated. Results: Most patients were women (53.23%) over 60 (38.71%). Several TTE measures showed promise for predicting PE: RV dilation (sensitivity 84%, specificity 77%), PA diameter (84% and 28%), TRG (66% and 58%), and PA acceleration time (92% and 62%). However, McConnell’s sign had low accuracy (area under ROC curve 0.62). Tricuspid annular plane systolic excursion (TAPSE) and PA acceleration time showed the best predictive performance (AUC 0.95-0.92) and can be used as screening tools for life-threatening massive PE.PESI index test, when compared to the gold standard CT scan (which shows lung involvement), does not provide additional valuable information and accurate predictions about the severity of PE. Conclusions: TAPSE and PaACT showed excellent predictive ability to CTPA-detected PE. RV dilation and PA diameter also showed good predictive capability. Findings support using some TTE indices to screen for PE severity and risk assessment before CTPA when access is limited.

Abstract Tu060: Unveiling Arrhythmogenic Right Ventricular Dysplasia In Pregnancy

Introduction: Arrhythmogenic right ventricular dysplasia (ARVD) is a rare autosomal dominant disease, caused by desmosomal gene mutations, and characterized by fibrofatty replacement of right ventricular (RV) myocardium with left ventricular (LV) involvement in advanced stages. It is mostly diagnosed between the second and forth decades of life and can present with ventricular tachycardia and arrhythmic sudden death. Here we present a case of ARVD diagnosis in a female in her forth pregnancy. Case description: A 28-year-old female, on her 27 th week of gestation (G4P3) was admitted to the hospital with preterm premature rupture of membranes. She also endorsed intermittent chest pressure, palpitations and shortness of breath. Her vital signs were stable, and electrocardiogram (ECG) revealed normal sinus rhythm with frequent premature ventricular contractions (PVCs) and T wave inversions in leads V1- V3. Laboratory studies showed normal troponin and D-dimer levels, and slightly elevated brain natriuretic peptide 240 pg/mL. Patient notably had frequent runs of monomorphic non-sustained ventricular tachycardia (NSVT) arising from RV apical territory, with left bundle branch morphology on telemetry. An echocardiogram revealed a dilated right atrium and RV with hypokinesis of RV; LV size and function were normal. Overall, patient met the revised task force diagnostic criteria for ARVD based on PVC morphology, abnormal ECG and dilated and hypokinetic RV. She had no sustained or hemodynamically unstable VT, no history of syncope or family history of sudden cardiac death and did not meet class I indication for implantable cardioverter defibrillator. She was started on oral metoprolol succinate 25 mg daily with which her arrhythmias significantly improved. She was recommended a cardiac magnetic resonance imaging and genetic testing for confirmation and to assess familial implications. Conclusion: Recognition of ARVD during pregnancy is challenging given the overlapping symptoms of normal pregnancy-related changes. Hormonal surge and sympathetic drive may have driven the increased frequency of NSVT in our patient and beta blocker was effective in managing these. Early recognition and tailored management are crucial to ensure the well-being of both the mother and the fetus. A close follow-up is necessary to understand the long-term implications for the patient and potential genetic predisposition in the family.

Large Right Atrial Size on Cardiac MRI is Associated with Post-operative Right Ventricular Dysfunction After the Cone Operation for Ebstein Anomaly.

The cone operation has revolutionized care for patients with Ebstein anomaly; however, acute post-operative right ventricular dysfunction (RVD) is common in this patient population. A single-center, retrospective review of 28 patients with Ebstein anomaly who underwent cardiac MRI (CMR) prior to cone reconstruction of the tricuspid valve was conducted. Measurements of atrial and ventricular size/function were assessed. Post-operative RVD was defined as the presence of moderate or severe systolic dysfunction on discharge echo. A two-tail t test was employed to compare the two groups. The average age at operation was 21.4years (range 1.6-57.8) and 14 (50%) had RVD at discharge. Patients with post-operative RVD had significantly larger pre-operative right atrial (RA) maximum volume (p = 0.016) and RA minimum volume (p = 0.030). Patients with RVD had smaller pre-operative left atrial (LA) minimum volume (p = 0.012). Larger pre-operative right ventricular (RV) end-systolic volume (p = 0.046), lower RV ejection fraction (0.029), and smaller left ventricular (LV) end-diastolic volume (p = 0.049) were significantly associated with post-operative RVD. Post-operative RVD was associated with longer milrinone duration (p = 0.009) and higher maximum milrinone dose (p = 0.005) but was not associated with intensive care or hospital length of stay (p = 0.19 and 0.67, respectively). Increased RA and RV dilation and decreased LA and LV volumes are associated with the development of post-operative RVD following cone operation for Ebstein anomaly. Post-operative RVD affects milrinone dose and duration but is not associated with increased length of stay.

Perinatal Cardiac Functional Adaptation in Hypoplastic Left Heart Syndrome: A Longitudinal Analysis

The perinatal transition is characterized by acute changes in cardiac loading. Compared with normal newborn combined cardiac output (CCO), single right ventricular (RV) output of neonates with hypoplastic left heart syndrome (HLHS) is markedly greater. The aim of this study was to examine the mechanisms of cardiac adaptation that facilitate this perinatal transition from late fetal to early neonatal life in HLHS. Prospectively recruited pregnancies complicated by fetal HLHS (n=35) and healthy control subjects (Ctrl; n=17) underwent serial echocardiography in late gestation (38±1weeks) and 6, 24, and 48hours after birth. Cardiac function was assessed using conventional, Doppler tissue, and speckle-tracking echocardiography. Term fetuses with HLHS had RV output comparable with Ctrl CCO via higher stroke volume. Compared with both left ventricular and RV indices of Ctrl, they exhibited globular and dilated right ventricles with reduced relative wall thickness (0.40±0.08 vs 0.49±0.10, P<.01), increased Tei index' (HLHS vs Ctrl left ventricle/Ctrl right ventricle: sphericity index, 0.9±0.25 vs 0.5±0.10/0.6±0.11; RV area index, 28±6 vs 15±3/17±5cm2/m2; Tei index', 0.65±0.11 vs 0.43±0.07/0.45±0.09; P<.0001 for all). Neonates with HLHS generated elevated RV cardiac output compared with Ctrl CCO via higher heart rate and stroke volume, with further RV dilatation, increased longitudinal systolic strain at 48hours (-17±4% vs -14±3%/14±5%) with reduced circumferential and rotational myocardial deformation and altered diastolic function. Neonates with HLHS also demonstrated right atrial enlargement with increased longitudinal strain: 6hours (33±12% vs 26±6%), 24hours (37±15% vs 26± 13%), and 48hours (38±11% vs 24±13%) (P<.0001). Term fetuses with HLHS exhibit altered RV geometry and RV systolic and diastolic functional parameters. After birth, further alterations in these cardiac parameters likely reflect adaptation to acutely altered RV loading from increasing cardiac output and pulmonary artery flow demands.

Right ventricular diastolic adaptation to pressure overload in different rat strains.

Different rat strains are used in various animal models of pulmonary hypertension and right ventricular (RV) failure. No systematic assessment has been made to test differences in RV response to pressure overload between rat strains. We compared RV adaptation to pulmonary trunk banding (PTB) in Wistar (W), Sprague Dawley (SD), and Fischer344 (F) rats by hemodynamic profiling focusing on diastolic function. Age-matched male rat weanlings were randomized to sham surgery (W-sham, n = 5; SD-sham, n = 4; F-sham, n = 4) or PTB (W-PTB, n = 8; SD-PTB, n = 8; F-PTB, n = 8). RV function was evaluated after 5 weeks by echocardiography, cardiac MRI, and invasive pressure-volume measurements. PTB caused RV failure and increased RV systolic pressures four-fold in all three PTB groups compared with sham. W- and SD-PTB had a 2.4-fold increase in RV end-systolic volume index compared with sham, while F-PTB rats were less affected. Diastolic and right atrial impairment were evident by increased RV end-diastolic elastance, filling pressure, and E/e' in PTB rats compared with sham, again F-PTB the least affected. In conclusions, PTB caused RV failure with signs of diastolic dysfunction. Despite a similar increase in RV systolic pressure, F-PTB rats showed less RV dilatation and a more preserved diastolic function compared with W- and SD-PTB.

Long-Term Echocardiographic and Clinical Outcomes After Invasive and Non-Invasive Therapies for Sub-Massive and Massive Acute Pulmonary Embolism

Acute pulmonary embolism (PE) is a significant cause of mortality in the hospital setting. The objective of this study was to outline the long-term outcomes after surgical and non-surgical management for patients with massive and submassive PE. Population cohort observational study evaluating all patients who presented to three tertiary hospitals in the state of Western Australia with access to cardiothoracic services over 5 years (2013-2018). Reviewed notes of all patients as well as radiology, linked mortality data and all available echocardiography studies at the primary hospital. In total, 245 patients were identified, of which 41 received surgical management and 204 non-surgical management; demographic data was similar. Clinically, the surgical group had higher rates of shock requiring vasopressors, severe bradycardia, or cardiopulmonary resuscitation prior to intervention. The 28-day mortality was not statistically significantly different between the surgical embolectomy group (2/41 [4.2%]) and the non-surgical group (17/201 [8.3%]) (p=0.382). There was no difference in 12-month mortality, including when this was adjusted for vasopressors, right ventricular (RV) strain, troponin, and brain natriuretic peptide. In the massive PE sub-group, 28-day mortality was not significantly different: 2/29 (6.9%) surgical group vs 7/34 (20.2%) non-surgical group (p=0.064). Higher rates of severe RV impairment and dilatation were present in the surgical group. All patients with available echocardiography studies at outpatient follow-up returned to normal or mild RV impairment. Patients who presented with massive or submassive PE had similar outcomes whether treated with surgical or non-surgical management. Surgical embolectomy is a safe option in a cardiothoracic centre setting.

New Right Ventricular Dysfunction in Pediatric Acute Respiratory Distress Syndrome on Venovenous Extracorporeal Membrane Oxygenation.

The development of new right ventricular (RV) dysfunction after cannulation to venovenous (VV) extracorporeal membrane oxygenation (ECMO) and its association with worse outcomes is increasingly recognized in adult patients, however, no studies have evaluated this phenomenon in pediatric patients. We report results of a single-center retrospective cohort study at a large academic children's hospital. New RV systolic dysfunction was present in 48% (12/25) of pediatric patients on VV ECMO for acute respiratory distress syndrome (ARDS). There was no statistically significant difference in survival, duration of mechanical ventilation, or hospital length of stay between those with and without RV dysfunction. Over half (5/9, 56%) of survivors with RV dysfunction on ECMO had RV dilation or RV hypertrophy on post-ECMO echocardiograms, and in two patients the RV dysfunction persisted for months following decannulation. Cardiac catheterization and autopsy reports suggested that echocardiographic assessment of RV systolic function alone may not be sufficient to diagnose clinically relevant RV injury. This is the first study to report the prevalence of RV dysfunction on VV ECMO for pediatric ARDS. Future multicenter collaboration is needed to create a clinically relevant definition of pediatric "RV injury" and to further evaluate risk factors and outcomes of RV dysfunction.

Does Cell-Type-Specific Silencing of Monoamine Oxidase B Interfere with the Development of Right Ventricle (RV) Hypertrophy or Right Ventricle Failure in Pulmonary Hypertension?

Increased mitochondrial reactive oxygen species (ROS) formation is important for the development of right ventricular (RV) hypertrophy (RVH) and failure (RVF) during pulmonary hypertension (PH). ROS molecules are produced in different compartments within the cell, with mitochondria known to produce the strongest ROS signal. Among ROS-forming mitochondrial proteins, outer-mitochondrial-membrane-located monoamine oxidases (MAOs, type A or B) are capable of degrading neurotransmitters, thereby producing large amounts of ROS. In mice, MAO-B is the dominant isoform, which is present in almost all cell types within the heart. We analyzed the effect of an inducible cardiomyocyte-specific knockout of MAO-B (cmMAO-B KO) for the development of RVH and RVF in mice. Right ventricular hypertrophy was induced by pulmonary artery banding (PAB). RV dimensions and function were measured through echocardiography. ROS production (dihydroethidium staining), protein kinase activity (PamStation device), and systemic hemodynamics (in vivo catheterization) were assessed. A significant decrease in ROS formation was measured in cmMAO-B KO mice during PAB compared to Cre-negative littermates, which was associated with reduced activity of protein kinases involved in hypertrophic growth. In contrast to littermates in which the RV was dilated and hypertrophied following PAB, RV dimensions were unaffected in response to PAB in cmMAO-B KO mice, and no decline in RV systolic function otherwise seen in littermates during PAB was measured in cmMAO-B KO mice. In conclusion, cmMAO-B KO mice are protected against RV dilatation, hypertrophy, and dysfunction following RV pressure overload compared to littermates. These results support the hypothesis that cmMAO-B is a key player in causing RV hypertrophy and failure during PH.