Heterogeneity of right ventricular echocardiographic parameters in systemic lupus erythematosus among four clinical subgroups, as stratified by clinical organ involvement in observational cohort.

BACKGROUND: Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease. Cardiac involvement in SLE is rare but plays an important prognostic role. The degree of cardiac involvement according to SLE subsets defined by non-cardiac manifestations is unknown. The objective of this study was to identify differences in transthoracic echocardiography (TTE) parameters associated with different SLE subgroups. METHODS: One hundred eighty-one patients who fulfilled the 2019 American College of Rheumatology/EULAR classification criteria for SLE and underwent baseline TTE were included in this cross-sectional study. We defined four subsets of SLE based on the predominant clinical manifestations. A multivariate multinomial regression analysis was performed to determine whether TTE parameters differed between groups. RESULTS: Four clinical subsets were defined according to non-cardiac clinical manifestations: group A (n=37 patients) showed features of mixed connective tissue disease, group B (n=76 patients) had primarily cutaneous involvement, group C (n=18) exhibited prominent serositis and group D (n=50) had severe, multi-organ involvement, including notable renal disease. Forty TTE parameters were assessed between groups. Per multivariate multinomial regression analysis, there were statistically significant differences in early diastolic tricuspid annular velocity (RV-Ea, p<0.0001), RV S' wave (p=0.0031) and RV end-diastolic diameter (p=0.0419) between the groups. Group B (primarily cutaneous involvement) had the lowest degree of RV dysfunction. CONCLUSION: When defining clinical phenotypes of SLE based on organ involvement, we found four distinct subgroups which showed notable differences in RV function on TTE. Risk-stratifying patients by clinical phenotype could help better tailor cardiac follow-up in this population.

Immediate cardiopulmonary responses to consecutive pulmonary embolism: a randomized, controlled, experimental study.

BACKGROUND: Acute pulmonary embolism (PE) induces ventilation-perfusion mismatch and hypoxia and increases pulmonary pressure and right ventricular (RV) afterload, entailing potentially fatal RV failure within a short timeframe. Cardiopulmonary factors may respond differently to increased clot burden. We aimed to elucidate immediate cardiopulmonary responses during successive PE episodes in a porcine model. METHODS: This was a randomized, controlled, blinded study of repeated measurements. Twelve pigs were randomly assigned to receive sham procedures or consecutive PEs every 15 min until doubling of mean pulmonary pressure. Cardiopulmonary assessments were conducted at 1, 2, 5, and 13 min after each PE using pressure-volume loops, invasive pressures, and arterial and mixed venous blood gas analyses. ANOVA and mixed-model statistical analyses were applied. RESULTS: Pulmonary pressures increased after the initial PE administration (p < 0.0001), with a higher pulmonary pressure change compared to pressure change observed after the following PEs. Conversely, RV arterial elastance and pulmonary vascular resistance was not increased after the first PE, but after three PEs an increase was observed (p = 0.0103 and p = 0.0015, respectively). RV dilatation occurred following initial PEs, while RV ejection fraction declined after the third PE (p = 0.004). RV coupling exhibited a decreasing trend from the first PE (p = 0.095), despite increased mechanical work (p = 0.003). Ventilatory variables displayed more incremental changes with successive PEs. CONCLUSION: In an experimental model of consecutive PE, RV afterload elevation and dysfunction manifested after the third PE, in contrast to pulmonary pressure that increased after the first PE. Ventilatory variables exhibited a more direct association with clot burden.

Right Ventricular Myocardial Infarction-A Tale of Two Ventricles: JACC Focus Seminar 1/5.

Right ventricular infarction (RVI) complicates 50% of cases of acute inferior ST-segment elevation myocardial infarction, and is associated with high in-hospital morbidity and mortality. Ischemic right ventricular (RV) systolic dysfunction decreases left ventricular preload delivery, resulting in low-output hypotension with clear lungs, and disproportionate right heart failure. RV systolic performance is generated by left ventricular contractile contributions mediated by the septum. Augmented right atrial contraction optimizes RV performance, whereas very proximal occlusions induce right atrial ischemia exacerbating hemodynamic compromise. RVI is associated with vagal mediated bradyarrhythmias, both during acute occlusion and abruptly with reperfusion. The ischemic dilated RV is also prone to malignant ventricular arrhythmias. Nevertheless, RV is remarkably resistant to infarction. Reperfusion facilitates RV recovery, even after prolonged occlusion and in patients with severe shock. However, in some cases hemodynamic compromise persists, necessitating pharmacological and mechanical circulatory support with dedicated RV assist devices as a "bridge to recovery."

Glenn shunt as a rescue strategy for acute right ventricular failure after right ventricular myocardial infarction.

We present the case of a 52-year-old woman with cardiogenic shock and refractory right ventricular failure due to spontaneous dissection of the right coronary artery. She remained dependent on mechanical support for several weeks. Both a right ventricular assist device implant and a bidirectional cavopulmonary anastomosis were explored as long-term support options. A history of malignancy and possible right ventricular functional recovery resulted in a decision in favour of the bidirectional cavopulmonary anastomosis and concomitant tricuspid valve annuloplasty. Postoperatively her clinical condition improved significantly, and she could be discharged home. Echocardiography showed normalization of right ventricular dimensions and slight improvement of right ventricular function.

Use of percutaneous mechanical circulatory support for right ventricular failure.

BACKGROUND: Utilization of right ventricular mechanical circulatory support (RV-MCS) devices has been limited by a lack of recognition of RV failure as well as a lack of availability and experience with RV-MCS. AIMS: We report a single-center experience with the use of percutaneous RV-MCS and report predictors of adverse outcomes. METHODS: This was a single-center retrospective cohort study. Data from consecutive patients who received RV-MCS for any indication between June 2015 and January 2022 were included. Data on baseline comorbidities, hemodynamics, and laboratory values were collected. The primary outcome was in-hospital mortality analyzed as a logistic outcome in a multivariable model. These variables were further ranked by their predictive value. RESULTS: Among 58 consecutive patients enrolled, the median age was 66 years, 31% were female and 53% were white. The majority of the patients (48%) were hospitalized for acute on chronic heart failure. The majority of the patients were SCAI SHOCK Stage D (67%) and 34 (64%) patients had MCS placed within 24 h of the onset of shock. Before placement of RV-MCS, median central venous pressure (CVP) and RV stroke work index were 20 mmHg and 8.9 g m/m2, respectively. Median serum lactate was 3.5 (1.6, 6.2) mmol/L. Impella RP was implanted in 50% and ProtekDuo in the remaining 50%. Left ventricular MCS was concomitantly used in 66% of patients. Twenty-eight patients (48.3%) died. In these patients, median serum lactate was significantly higher (4.1 [2.3, 13.0] vs. 2.2 [1.4, 4.0] mmol/L, p = 0.007) and a trend toward higher median CVP (24 [18, 31] vs. 19 [14, 24] mmHg, p = 0.052). In the multivariable logistic model, both serum lactate and CVP before RV-MCS placement were independent predictors of in-hospital mortality. Serum lactate had the highest predictive value. CONCLUSION: In our real-world cohort, 52% of patients treated with RV-MCS survived their index hospitalization. Serum lactate at presentation and CVP were the strongest predictors of in-hospital mortality.

The Sugen/Hypoxia Rat Model for Pulmonary Hypertension and Right Heart Failure.

Pulmonary hypertension (PH) is a devastating disease, characterized by complex remodeling of the pulmonary vasculature. PH is classified into five groups based on different etiology, pathology, as well as therapy and prognosis. Animal models are essential for the study of underlying mechanisms, pathophysiology, and preclinical testing of new therapies for PH. The complexity of the disease with different clinical entities dictates the necessity for more than one animal model to resemble PH, as a single model cannot imitate the broad spectrum of human PH.Here we describe a detailed protocol for creating a rat model of PH with right ventricular (RV) failure. Furthermore, we present how to characterize it hemodynamically by invasive measurements of RV and pulmonary arterial (PA) pressures. Animals subjected to this model display severe pulmonary vascular remodeling and RV dysfunction. In this model, rats undergo a single subcutaneous injection of Sugen (SU5416, a vascular endothelial growth factor inhibitor) and are immediately exposed to chronic hypoxia in a hypoxia chamber for 3-6 weeks. This Sugen/Hypoxia rat model resembles Group 1 PH.

A Dynamic Sheep Model to Induce Pulmonary Hypertension and Right Ventricular Failure.

Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing novel therapeutics for PH requires a clinically relevant large animal model of increased pulmonary vascular resistance and RVF. This manuscript describes the method to induce an ovine PH-RVF model that utilizes left pulmonary artery (LPA) ligation, progressive main pulmonary artery (MPA) banding, and insertion of an RV pressure line for monitoring. The PA cuff and RV pressure tubing are connected to subcutaneous access ports. This model of PH-RVF is a versatile platform to control not only the disease severity, but also the RV's phenotypic response. Subjects undergo progressive PA band adjustments twice per week for approximately 9 weeks with sequential measures of RV pressure, PA cuff pressures, and mixed venous blood gas (SvO2). Subjects can further be exercised on a livestock treadmill while hemodynamic parameters are captured. At the initiation and endpoint of this model, ventricular function and dimensions are assessed using echocardiography. In this model, RV mean and systolic pressure increased to 28 ± 5 and 57 ± 7 mmHg at week 1, and further to 44 ± 7 and 93 ± 18 mmHg by week 9, respectively. Echocardiography demonstrates characteristic findings of PH-RVF, notably RV dilation, increased wall thickness, and septal bowing. The rate of PA banding has a significant impact on SvO2 and thus the model can be titrated to elicit varying RV phenotypes. When the PA cuff is tightened rapidly, it can lead to a precipitous decline in SvO2, leading to RV decompensation, whereas a slower, more paced strategy leads to an adaptive RV stress-load response that maintains physiologic SvO2. A faster rate of PA banding will also lead to more severe liver fibrosis. The addition of controlled exercise provides a useful platform for assessing the effects of physical exertion in a PH-RVF model. This chronic PH-RVF model provides a valuable tool for studying molecular mechanisms, developing diagnostic biomarkers, and evaluating mechanical circulatory support systems.

Right ventricular preload and afterload challenge induces contractile dysfunction and arrhythmia in isolated hearts of dystrophin-deficient male mice.

Duchenne muscular dystrophy (DMD) is an X-linked recessive myopathy due to mutations in the dystrophin gene. Diaphragmatic weakness in DMD causes hypoventilation and elevated afterload on the right ventricle (RV). Thus, RV dysfunction in DMD develops early in disease progression. Herein, we deliver a 30-min sustained RV preload/afterload challenge to isolated hearts of wild-type (Wt) and dystrophic (Dmdmdx-4Cv) mice at both young (2-6 month) and middle-age (8-12 month) to test the hypothesis that the dystrophic RV is susceptible to dysfunction with elevated load. Young dystrophic hearts exhibited greater pressure development than wild type under baseline (Langendorff) conditions, but following RV challenge exhibited similar contractile function as wild type. Following the RV challenge, young dystrophic hearts had an increased incidence of premature ventricular contractions (PVCs) compared to wild type. Hearts of middle-aged wild-type and dystrophic mice had similar contractile function during baseline conditions. After RV challenge, hearts of middle-aged dystrophic mice had severe RV dysfunction and arrhythmias, including ventricular tachycardia. Following the RV load challenge, dystrophic hearts had greater lactate dehydrogenase (LDH) release than wild-type mice indicative of damage. Our data indicate age-dependent changes in RV function with load in dystrophin deficiency, highlighting the need to avoid sustained RV load to forestall dysfunction and arrhythmia.

The impact of unilateral pulmonary artery stenosis on right ventricular to pulmonary arterial coupling in patients with transposition of the great arteries.

BACKGROUND: Unilateral pulmonary artery (PA) stenosis is common in the transposition of the great arteries (TGA) after arterial switch operation (ASO) but the effects on the right ventricle (RV) remain unclear. AIMS: To assess the effects of unilateral PA stenosis on RV afterload and function in pediatric patients with TGA-ASO. METHODS: In this retrospective study, eight TGA patients with unilateral PA stenosis underwent heart catheterization and cardiac magnetic resonance (CMR) imaging. RV pressures, RV afterload (arterial elastance [Ea]), PA compliance, RV contractility (end-systolic elastance [Ees]), RV-to-PA (RV-PA) coupling (Ees/Ea), and RV diastolic stiffness (end-diastolic elastance [Eed]) were analyzed and compared to normal values from the literature. RESULTS: In all TGA patients (mean age 12 ± 3 years), RV afterload (Ea) and RV pressures were increased whereas PA compliance was reduced. RV contractility (Ees) was decreased resulting in RV-PA uncoupling. RV diastolic stiffness (Eed) was increased. CMR-derived RV volumes, mass, and ejection fraction were preserved. CONCLUSION: Unilateral PA stenosis results in an increased RV afterload in TGA patients after ASO. RV remodeling and function remain within normal limits when analyzed by CMR but RV pressure-volume loop analysis shows impaired RV diastolic stiffness and RV contractility leading to RV-PA uncoupling.

Regional Strain of Right Ventricle From Computed Tomography Improves Risk Stratification of Right Ventricle Failure.

Patients who undergo implantation of a left ventricular assist device (LVAD) are at a high risk for right ventricular failure (RVF), presumably due to poor right ventricular (RV) function before surgery. Cine computerized tomography (cineCT) can be used to evaluate RV size, function, and endocardial strain. However, CT-based strain measures in patients undergoing workup for LVAD implantation have not been evaluated. We quantified RV strain in the free wall (FW) and septal wall (SW) in patients with end-stage heart failure using cineCT. Compared to controls, both FW and SW strains were significantly impaired in heart failure patients. The difference between FW and SW strains predicted RV failure after LVAD implantation (area-under-the curve [AUC] = 0.82). Cine CT strain can be combined with RV volumetry to risk-stratify patients. In our study, patients with preserved RV volumes and poor strain had a higher rate of RV failure (57%), than those with preserved volume and preserved strain (0%). This suggests that CT could improve risk stratification of patients receiving LVADs and that strain metrics were particularly useful in risk-stratifying patients with preserved RV volumes.

Advanced hemodynamic and cluster analysis for identifying novel RV function subphenotypes in patients with pulmonary hypertension.

BACKGROUND: Quantifying right ventricular (RV) function is important to describe the pathophysiology of in pulmonary hypertension (PH). Current phenotyping strategies in PH rely on few invasive hemodynamic parameters to quantify RV dysfunction severity. The aim of this study was to identify novel RV phenotypes using unsupervised clustering methods on advanced hemodynamic features of RV function. METHODS: Participants were identified from the University of Arizona Pulmonary Hypertension Registry (n = 190). RV-pulmonary artery coupling (Ees/Ea), RV systolic (Ees), and diastolic function (Eed) were quantified from stored RV pressure waveforms. Consensus clustering analysis with bootstrapping was used to identify the optimal clustering method. Pearson correlation analysis was used to reduce collinearity between variables. RV cluster subphenotypes were characterized using clinical data and compared to pulmonary vascular resistance (PVR) quintiles. RESULTS: Five distinct RV clusters (C1-C5) with distinct RV subphenotypes were identified using k-medoids with a Pearson distance matrix. Clusters 1 and 2 both have low diastolic stiffness (Eed) and afterload (Ea) but RV-PA coupling (Ees/Ea) is decreased in C2. Intermediate cluster (C3) has a similar Ees/Ea as C2 but with higher PA pressure and afterload. Clusters C4 and C5 have increased Eed and Ea but C5 has a significant decrease in Ees/Ea. Cardiac output was high in C3 distinct from the other clusters. In the PVR quintiles, contractility increased and stroke volume decreased as a function of increased afterload. World Symposium PH classifications were distributed across clusters and PVR quintiles. CONCLUSIONS: RV-centric phenotyping offers an opportunity for a more precise-medicine-based management approach.

Mitochondrial Integrity Is Critical in Right Heart Failure Development.

Molecular processes underlying right ventricular (RV) dysfunction (RVD) and right heart failure (RHF) need to be understood to develop tailored therapies for the abatement of mortality of a growing patient population. Today, the armament to combat RHF is poor, despite the advancing identification of pathomechanistic processes. Mitochondrial dysfunction implying diminished energy yield, the enhanced release of reactive oxygen species, and inefficient substrate metabolism emerges as a potentially significant cardiomyocyte subcellular protagonist in RHF development. Dependent on the course of the disease, mitochondrial biogenesis, substrate utilization, redox balance, and oxidative phosphorylation are affected. The objective of this review is to comprehensively analyze the current knowledge on mitochondrial dysregulation in preclinical and clinical RVD and RHF and to decipher the relationship between mitochondrial processes and the functional aspects of the right ventricle (RV).