Right Ventricular Contractility Research Articles

Right ventricular pressure-strain relationship-derived myocardial work reflects contractility: Validation with invasive pressure-volume analysis

Three-dimensional (3D) echocardiography-derived right ventricular (RV) ejection fraction (EF) and global longitudinal strain (GLS) are valuable RV functional markers; nevertheless, they are substantially load-dependent. Global myocardial work index (GMWI) is a novel parameter calculated by the area of the RV pressure-strain loop. By adjusting myocardial deformation to instantaneous pressure, it may reflect contractility.To test this hypothesis, we enrolled 60 patients who underwent RV pressure-conductance catheterization to determine load-independent markers of RV contractility and ventriculo-arterial coupling. Detailed 3D echocardiography was also performed, and we calculated RV EF, RV GLS, and using the RV pressure trace curve, RV GWMI.While neither RV EF nor GLS correlated with Ees, GMWI strongly correlated with Ees. In contrast, RV EF and GLS showed a relationship with Ees/Ea. By dividing the population based on their Reveal Lite 2 risk classification, different characteristics were seen among the subgroups.RV GMWI may emerge as a useful clinical tool for risk stratification and follow-up in patients with RV dysfunction.

Right ventricular performance during acute hypoxic exercise.

Acute hypoxia increases pulmonary arterial (PA) pressures, though its effect on right ventricular (RV) function is controversial. The objective of this study was to characterize exertional RV performance during acute hypoxia. Ten healthy participants (34±10 years, 7males) completed three visits: visits 1 and 2 included non-invasive normoxic (fraction of inspired oxygen ( )=0.21) and isobaric hypoxic ( =0.12) cardiopulmonary exercise testing (CPET) to determine normoxic/hypoxic maximal oxygen uptake ( ). Visit 3 involved invasive haemodynamic assessments where participants were randomized 1:1 to either Swan-Ganz or conductance catheterization to quantify RV performance via pressure-volume analysis. Arterial oxygen saturation was determined by blood gas analysis from radial arterial catheterization. During visit 3, participants completed invasive submaximal CPET testing at 50% normoxic and again at 50% hypoxic ( =0.12). Median (interquartile range) values for non-invasive values during normoxic and hypoxic testing were 2.98 (2.43, 3.66) l/min and 1.84 (1.62, 2.25) l/min, respectively (P<0.0001). Mean PA pressure increased significantly when transitioning from rest to submaximal exercise during normoxic and hypoxic conditions (P=0.0014). Metrics of RV contractility including preload recruitable stroke work, dP/dtmax , and end-systolic pressure increased significantly during the transition from rest to exercise under normoxic and hypoxic conditions. Ventricular-arterial coupling was maintained during normoxic exercise at 50% . During submaximal exercise at 50% of hypoxic , ventricular-arterial coupling declined but remained within normal limits. In conclusion, resting and exertional RV functions are preserved in response to acute exposure to hypoxia at an =0.12 and the associated increase in PA pressures. KEY POINTS: The healthy right ventricle augments contractility, lusitropy and energetics during periods of increased metabolic demand (e.g. exercise) in acute hypoxic conditions. During submaximal exercise, ventricular-arterial coupling decreases but remains within normal limits, ensuring that cardiac output and systemic perfusion are maintained. These data describe right ventricular physiological responses during submaximal exercise under conditions of acute hypoxia, such as occurs during exposure to high altitude and/or acute hypoxic respiratory failure.

Application of an echocardiographic index to characterize right ventricular-pulmonary arterial coupling in heart failure.

Heart failure (HF), with its high morbidity and mortality, remains a global public health issue. Right ventricular (RV) dysfunction is a sign of deterioration in the natural history of HF, and a thorough evaluation of the relationship between RV contractility and its afterload through RV-pulmonary arterial (RV-PA) coupling can aid in accurately assessing overall RV function. The ratio of RV end-systolic elastance (Ees) to pulmonary arterial elastance (Ea) invasively measured by right heart catheterization served as the gold standard for evaluating RV-PA coupling. An echocardiographic index termed tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) has been shown to correlate well with Ees/Ea. TAPSE/PASP is recognized as a non-invasive surrogate of RV-PA coupling and has been extensively studied in patients with HF. This review briefly describes the methods of assessing RV-PA coupling, mainly discussing echocardiography, summarizes the clinical utility of TAPSE/PASP in patients with different HF types, and provides an overview of the available literature.

Impact of Interventricular Interaction on Ventricular Function: Insights From Right Ventricular Pressure-Volume Analysis.

Interventricular interactions may be responsible for the decline in ventricular performance observed in various disease states that primarily affect the contralateral ventricle. This study sought to quantify the impact of such interactions on right ventricular (RV) size and function using clinically stable individuals with left ventricular assist devices (LVADs) as a model for assessing RV hemodynamics while LV loading conditions were acutely manipulated by changing device speed during hemodynamic optimization studies (ie, ramp tests). The investigators recorded RV pressure-volume loops with a conductance catheter at various speeds during ramp tests in 20 clinically stable HeartMate3 recipients. With faster LVAD speeds and greater LV unloading, indexed RV end-diastolic volume increased (72.28 ± 15.07mL at low speed vs 75.95 ± 16.90 at high speed; P = 0.04) whereas indexed end-systolic volumes remained neutral. This resulted in larger RV stroke volumes and shallower end-diastolic pressure-volume relationships. Concurrently, RV end-systolic pressure decreased (31.58 ± 9.75mL at low speed vs 29.58 ± 9.41mL at high speed; P = 0.02), but contractility, as measured by end-systolic elastance, did not change significantly. The reduction in RV end-systolic pressure was associated with a reduction in effective arterial elastance from 0.65 ± 0.43mmHg/mL at low speed to 0.54 ± 0.33mmHg/mL at high speed (P = 0.02). Interventricular interactions resulted in improved RV compliance, diminished afterload, and did not reduce RV contractility. These data challenge the prevailing view that interventricular interactions compromise RV function, which has important implications for the understanding of RV-LV interactions in various disease states, including post-LVAD RV dysfunction.

Right Ventricular Function in Surgical Treatment of Left Heart.

Aim The aim of this study was to evaluate right ventricular (RV) function during left chamber surgery.Material and methods This was a single-site prospective cohort study. The study included 197 patients with valvular pathology of heart left chambers. Mean age of patients was 58 [47; 65] years. Precordial echocardiography was performed preoperatively and within one week after surgery.Results Decreased parameters of the right ventricular (RV) longitudinal function and global contractile function were observed postoperatively in the majority of patients. More noticeable decreases were observed in parameters of the longitudinal function (p&lt;0.001). Analysis of the changes in RV contractility depending on the underlying pathology revealed the greatest changes in the contractile function in the mitral insufficiency group. In the mitral stenosis group, the greatest difference was observed in the tricuspid annular systolic excursion (TAPSE) (p=0.027). In the groups with aortic defects, all parameters of RV contractile function, except for the fractional area change (FAC), showed statistically significant decreases after correction of the underlying defect (p&lt;0.05).Conclusions Surgical intervention for left heart valvulopathy can result in a decrease in RV function unrelated with systolic deficit of the left ventricle. Modern technologies allow multi-vector assessment of the RV contractile function. To assess the RV function, it is advisable to use a combination of parameters that reflect both global and longitudinal function.

Right ventricular function in moderate-to-severe ventricular tricuspid regurgitation: Is there a pseudo-normalization of conventional echocardiographic parameters?

Abstract Background A reliable evaluation of right ventricular (RV) function in the presence of moderate-to-severe tricuspid regurgitation (m/s-TR) is of paramount importance for surgical or interventional risk stratification. Due to the significant systolic regurgitation of blood from the RV to the low-pressure right atrium, conventional echocardiographic parameters could appear normal and thus overestimate RV function (pseudo-normal). The aim of this study was to analyse and compare RV function in trace TR versus m/s-TR by the invasive pressure-volume-loop (PV-loop) technique, the gold standard of RV function analysis, with conventional echocardiographic indices in patients with the ventricular form of mild/no vs. m/s-TR. Methods The study was conducted in 134 patients with HFrEF in a post-hoc analysis (110 from the Magdeburg CRT Responder Trial, and 24 from a local CRT-optimization trial). Results The logistic regression analysis demonstrated that RV size (RV-end-diastolic volume, RVEDV) and RV function (measured as RV fractional area change, FAC), TAPSE, and lower fractional shortening (FS) of proximal the RV-outflow tract (RVOTprox) was closely associated with PV-loop-derived RV total afterload (pulmonary arterial elastance, Ea) and coupling of RV contractility (end-systolic RV elastance, Ees) to Ea (Ees/Ea) (all, p&amp;lt;0.001). Compared to trace TR (n=98, 73%), m/s-TR (n=36, 27%) was accompanied with significant higher total afterloads (Ea: 0.75 vs.0.41, p&amp;lt;0.001) and lower RV-PA coupling ratios (Ees/Ea, 0.4 vs. 0.79, p&amp;lt;0.001). This was associated with enlarged RVs (RVEDV: 210ml vs. 166ml), lower FAC (31% vs. 50%), TAPSE (13mm vs. 18mm), and RVOTprox (22% vs. 39%) (all p&amp;lt;0.001). For better comparability between trace TR and m/s-TR tertiles (T1-T3) of similar afterloads (Ea) were formed. The m/s-TR patients showed significant lower RV-PA coupling ratios than trace TR at the lower two Ea tertiles T1 (p=0.034) and T2 (p&amp;lt;0.001). At Ea T3 the difference was no longer significant (p=0.055). The hemodynamic data are mirrored by significant lower FACs, FS RVOTprox, and TAPSE at T1 and T2 (all p&amp;lt;0.05), and a nonsignificant difference at T3 in m/s-TR. In conclusion: In our cohort of HFrEF patients, echocardiographic RV function reflects very closely the hemodynamic coupling efficiency of RV contractility (Ees) to afterload (Ea) and seems independent from the extent of TR. We found no evidence for pseudo-normal or overestimated echocardiographic RV function in m/s-TR.

Abstract 15773: The Forgotten Ventricle: Insight Into Dynamic Effects of Left Ventricular Assist Device Ramp on Right Ventricle Function

Introduction: Left ventricular assist devices (LVAD) with magnetically levitated impellers have become standard due to hemocompatibility and survival profile. To optimize LVAD speeds, we previously introduced simultaneous right and left heart (RH/LH) catheterization during ramp studies. Here, we report pairing of this approach with pressure-volume (PV) assessment in a patient with a HeartMate 3 LVAD with mitral regurgitation (MR). The combined approach evaluated left ventricular (LV) hemodynamics and right ventricular (RV) PV-relationships during ramp testing. Methods: A 68-year-old male with ischemic cardiomyopathy, two years following HeartMate3 implantation, presented with NYHA class III symptoms. To evaluate for dyspnea, he underwent a RH/LH catheterization ramp study. RV PV-loops were created by use of a conductance catheter system, allowing creation of PV loops. Results: At the baseline LVAD speed of 5300 rotations per minute (RPM), right atrial pressure was elevated at 16 mmHg and pulmonary artery (PA) pressure of 26 mmHg. Left-end diastolic pressure (LVEDP) was elevated (16mmHg). Baseline cardiac index (CI) was 2.01 L/min/m 2 . Ramp testing was performed, increasing speeds from 5300 to 5800 RPM. Progressive LV unloading was observed with a 5 mmHg drop in LVEDP and a 3 mmHg drop in PA pressure. However, RV PV loop monitoring revealed a negative impact on RV contractility with the maximal elastance (Emax) slope demonstrating a 22% reduction. Furthermore, a 17% reduction in RV stroke volume was documented, while diastolic function remained unchanged. Thus, despite excellent LV offloading and diminishment of RV afterload, the significant negative impact on Emax resulted in no net increase in CI (+0.04 L/min/m 2 ) during the ramp evaluation. Inotrope therapy was initiated for RV function with increased LVAD RPM to outcompete MR. Conclusions: While RH/LH catheterization provides a real-time perspective of the interventricular relationship during ramp, the impact of increasing LVAD speeds on RV function has yet to be directly measured. Here, the RV PV loop relationship during LVAD ramp showed that although LVAD speed increases in the setting of MR may facilitate LV unloading, a drop in RV afterload did not compensate for reduction in RV contractility.

Abstract 15158: Prognostic Impact of Right Ventricular-Pulmonary Arterial Coupling Ratio in Patients Undergoing Transcatheter Aortic Valve Replacement

Introduction: Right ventricular (RV) dysfunction is known as an important prognostic factor in heart failure. As reduced RV systolic reserve, RV contractility no longer increases against afterload, resulting in lower ratios of RV function to pulmonary artery (PA) pressure, known as RV-PA coupling ratios. Hypothesis: The assessment of RV-PA coupling ratios provides prognostic information for patients undergoing transcatheter aortic valve replacement (TAVR). Methods and Results: A total of 540 patients with TAVR (age, 84 ± 6 years; 186 men, 354 women) were included in this study. The RV-PA coupling ratio was calculated by dividing the tricuspid annular plane systolic excursion (TAPSE) by the PA systolic pressure (PASP) using transthoracic echocardiography before TAVR. Based on the median TAPSE/PASP (0.584 mm/mmHg), the patients were divided into two groups. Kaplan-Meier analysis demonstrated a higher incidence of adverse cardiac events (cardiac death and heart failure hospitalization) in the group with a low TAPSE/PASP ratio (log-rank test, P &lt;0.001). In multivariate Cox regression analysis, TAPSE/PASP was identified as an independent prognostic parameter (adjusted hazard ratio, 0.259; P = 0.028), whereas neither TAPSE alone nor PASP alone demonstrated any significant prognostic value. Conclusion: The RV-PA coupling ratio serves as a prognostic predictor for adverse cardiac events in patients undergoing TAVR.

Echocardiographic Evaluation of the Right Heart in Pulmonary Hypertension

Pulmonary hypertension (PH) is characterized by increased right ventricular (RV) afterload, which is accommodated early by dramatic increases in RV contractility to maintain right ventriculoarterial coupling. Related to its tissue biology, characteristics of RV contractility differ from those of the left ventricle (LV). As the RV undergoes adaptation in PH, echocardiographic signs emerge which can help identify PH and can be reassessed to noninvasively prognosticate outcomes in PH. Many of these indices can be calculated from standard echocardiographic views without significant modification to scanning procedures. This review will discuss contemporary diagnosis of PH, highlighting the role of echocardiography in this process. We will describe the differences between the LV and RV, including adaptations of the RV in PH, and how these factors impact echocardiographic assessment. We will conclude with a discussion of specific echocardiographic parameters and describe their role in diagnosis and reassessment. Routine assessment of the right heart improves noninvasive risk stratification in PH, may reduce delays in diagnosis, and ultimately may impact the significant and potentially modifiable disease burden in this patient population.

Right Ventricular Contractility and Pulmonary Arterial Coupling After Less Invasive Left Ventricular Assist Device Implantation.

Right ventricular failure contributes significantly to morbidity and mortality after left ventricular assist device implantation. Recent data suggest a less invasive strategy (LIS) via thoracotomy may be associated with less right ventricular failure than conventional median sternotomy (CMS). However, the impact of these approaches on load-independent right ventricular (RV) contractility and RV-pulmonary arterial (RV-PA) coupling remains uncertain. We hypothesized that the LIS approach would be associated with preserved RV contractility and improved RV-PA coupling compared with CMS. We performed a retrospective study of patients who underwent durable, centrifugal left ventricular assist device implantation and had paired hemodynamic assessments before and after implantation. RV contractility (end-systolic elastance [Ees]), RV afterload (pulmonary effective arterial elastance [Ea]), and RV-PA coupling (Ees/Ea) were determined using digitized RV pressure waveforms. Forty-two CMS and 21 LIS patients were identified. Preimplant measures of Ees, Ea, and Ees/Ea were similar between groups. After implantation, Ees declined significantly in the CMS group (0.60-0.40, p = 0.008) but not in the LIS group (0.67-0.58, p = 0.28). Coupling (Ees/Ea) was unchanged in CMS group (0.54-0.59, p = 0.80) but improved significantly in the LIS group (0.58-0.71, p = 0.008). LIS implantation techniques may better preserve RV contractility and improve RV-PA coupling compared with CMS.

Isolated Right Ventricular Infarction without Right Ventricular Dysfunction: A Case Report

BACKGROUND: Myocardial infarction is the leading cause of the occlusion of the coronary artery. Meanwhile, right ventricular myocardial infarction (RVMI) is usually associated with inferior left ventricular infarction in 10–50% of cases. We presented isolated RV infarcts which are rare cases that happen in only 3% of total myocardial infarction. CASE PRESENTATION: We presented a case of a 67-year-old man with sudden chest pain, shortness of breath, and a history of diabetes mellitus. From his 12 lead electrocardiogram, there is no specific ST elevation yet elevation in V3R and V4R and elevated troponin I highly sensitive value. The patient developed junctional bradycardia and early percutaneous coronary intervention backup temporary pacemaker showed total occlusion in the proximal right coronary artery (RCA) CONCLUSION: The RVMI commonly occurs in the dominant RCA that also supplies the sinoatrial node and atrioventricular node. Therefore, due to its location that passed through the RCA, bradycardia to complete heart block may happen. Isolated right ventricular (RV) infarction may happen because either RV marginal as the predominant location is occluded, or non-dominant RCA occluded by thrombus. RV infarction may impair RV contractility causing a decrease in RV stroke volume and this condition leads to hypotension, shock, and severe hemodynamic derangement. Meanwhile, acute proximal RCA occlusions do not result in significant RV necrosis, one of the reasons is collateral flow from the left coronary system further protects from RV dysfunctions in our patient.

Preeclampsia and risk of maternal pulmonary hypertension at high altitude in Bolivia.

Women with a history of preeclampsia (PE) have a greater risk of pulmonary arterial hypertension (PAH). In turn, pregnancy at high altitude is a risk factor for PE. However, whether women who develop PE during highland pregnancy are at risk of PAH before and after birth has not been investigated. We tested the hypothesis that during highland pregnancy, women who develop PE are at greater risk of PAH compared to women undergoing healthy highland pregnancies. The study was on 140 women in La Paz, Bolivia (3640m). Women undergoing healthy highland pregnancy were controls (C, n = 70; 29 ± 3.3 years old, mean±SD). Women diagnosed with PE were the experimental group (PE, n = 70, 31 ± 2 years old). Conventional (B- and M-mode, PW Doppler) and modern (pulsed wave tissue Doppler imaging) ultrasound were applied for cardiovascular íííassessment. Spirometry determined maternal lung function. Assessments occurred at 35 ± 4 weeks of pregnancy and 6 ± 0.3 weeks after birth. Relative to highland controls, highland PE women had enlarged right ventricular (RV) and right atrial chamber sizes, greater pulmonary artery dimensions and increased estimated RV contractility, pulmonary artery pressure and pulmonary vascular resistance. Highland PE women had lower values for peripheral oxygen saturation, forced expiratory flow and the bronchial permeability index. Differences remained 6 weeks after birth. Therefore, women who develop PE at high altitude are at greater risk of PAH before and long after birth. Hence, women with a history of PE at high altitude have an increased cardiovascular risk that transcends the systemic circulation to include the pulmonary vascular bed.

Combined use of right ventricular coupling and pulmonary arterial elastance as a comprehensive stratification approach for right ventricular function.

Right ventricular (RV)-pulmonary arterial uncoupling is the consequence of increased afterload and/or decreased RV contractility. However, the combination of arterial elastance (Ea) and end-systolic elastance (Ees)/Ea ratio to assess RV function is unclear. We hypothesized that the combination of both could comprehensively assess RV function and refine risk stratification. The median Ees/Ea ratio (0.80) and Ea (0.59mmHg/mL) were used to classify 124 advanced heart failure patients into four groups. RV systolic pressure differential was defined as end-systolic pressure (ESP) minus beginning-systolic pressure (BSP). Patients among different subsets showed dissimilar New York Heart Association functional class (V=0.303, P=0.010), distinct tricuspid annular plane systolic excursion/ pulmonary artery systolic pressure (mm/mmHg) (0.65 vs. 0.44 vs. 0.32 vs. 0.26, P<0.001), and diverse prevalence of pulmonary hypertension (33.3% vs. 35% vs. 90% vs. 97.6%, P<0.001). By multivariate analysis, Ees/Ea ratio (hazard ratio [HR] 0.225, P=0.004) and Ea (HR 2.194, P=0.003) were independently associated with event-free survival. Patients with Ees/Ea ratio >0.80 and Ea <0.59mmHg/mL had better outcomes (P<0.05). In patients with Ees/Ea ratio >0.80, those with Ea ≥0.59mmHg/mL had a higher adverse outcome risk (P<0.05). Ees/Ea ratio ≤0.80 was associated with adverse outcomes, even when Ea was <0.59mmHg/mL (P<0.05). Approximately 86% of patients with ESP-BSP >5mmHg had an Ees/Ea ratio ≤0.80 and/or an Ea ≥0.59mmHg/mL (V=0.336, P=0.001). Combined use of Ees/Ea ratio and Ea could be a comprehensive approach to assessing RV function and predicting outcomes. An exploratory analysis demonstrated that Ees/Ea ratio and Ea might be roughly estimated based on RV systolic pressure differential.

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.

Features of echocardiographic examination in patients with COVID-19

Novel coronavirus infection has become one of urgent health problems of the 21st century. The associated disorders often result in the development of cardiopulmonary pathology, which requires creation of a new paradigm in diagnosis and treatment. Studies performed during the pandemic have demonstrated an important role of echocardiography (EchoCG) in diagnosis of right ventricular (RV) dysfunction in patients with respiratory insufficiency in COVID-19. The analysis of EchoCG parameters with a high prognostic value showed that in EchoCG, a special attention should be paid to right heart dimensions, RV contractility, and pulmonary artery (PA) systolic pressure, which are the most sensitive indexes of RV afterload and indirect markers of pulmonary disease severity. RV FAC can be recommended for evaluation of the RV systolic function as the most informative variable. Also, it was demonstrated that the RV longitudinal strain has an additional significance for early identification of signs of systolic dysfunction and risk stratification in patients with COVID-19. In addition to the effectiveness and reproducibility of this method, an important advantage of EchoCG is its availability, possibility of saving images for remote interpretation by other specialists, and tracking changes in morphological and functional parameters of the heart. Thus, the analysis of international literature suggests that EchoCG plays an important role in prediction of severe cardiopulmonary disorders and timely selection of the treatment for patients with COVID-19. For these reasons, EchoCG should serve as an additional method of clinical evaluation, particularly in persons with moderate or severe disease.

The impact of right ventricular hemodynamics on the performance of a left ventricular assist device in a numerical simulation model.

Left ventricular assist devices (LVADs) have been established as alternative to heart transplantation for patients with end-stage heart failure refractory to medical therapy. Right heart failure (RHF) after LVAD implantation is associated with inferior outcome. Its preoperative anticipation may influence the selection between a pure left ventricular and a biventricular device type and, thus, improve outcomes. Reliable algorithms to predict RHF are missing. A numerical model was used for simulation of a cardiovascular circulation. The LVAD was placed as parallel circuit between left ventricle and aorta. In contrast to other studies, the dynamic hydraulic behavior of a pulsatile LVAD was replaced by that of a continuous LVAD. A variety of hemodynamic states was tested mimicking different right heart conditions. Adjustable parameters included heart rate (HR), pulmonary vascular resistance (PVR), tricuspid regurgitation (TR), right ventricular contractility (RVC) and pump speed. Outcome parameters comprised central venous pressure (CVP), mean pulmonary artery pressure (mPAP), cardiac output (CO) and occurrence of suction. Alteration of HR, PVR, TR, RVC and pump speed resulted in diverse effects on CO, CVP and mPAP, resulting in improvement, impairment or no change of the circulation, depending on the degree of alteration. The numerical simulation model allows prediction of circulatory changes and LVAD behaviour following variation of hemodynamic parameters. Such a prediction may be of particular advantage to anticipate RHF after LVAD implantation. It may help preoperatively to choose the appropriate strategy of only left ventricular or both left and right ventricular support.

Metabolic profiling of in vivo right ventricular function and exercise performance in pulmonary arterial hypertension

Right ventricular (RV) adaptation is the principal determinant of outcomes in pulmonary arterial hypertension (PAH), however, RV function is challenging to assess. RV responses to hemodynamic stressors are particularly difficult to interrogate without invasive testing. This study sought to identify metabolomic markers of in vivo right ventricular function and exercise performance in PAH. Consecutive subjects with PAH (n = 23) underwent rest and exercise right heart catheterization with multibeat pressure volume loop analysis. Pulmonary arterial blood was collected at rest and during exercise. Mass spectrometry-based targeted metabolomics were performed, and metabolic associations with hemodynamics and comprehensive measures of RV function were determined using sparse partial least squares regression. Metabolite profiles were compared with N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) measurements for accuracy in modeling ventriculo-arterial parameters. Thirteen metabolites changed in abundance with exercise, including metabolites reflecting increased arginine bioavailability, precursors of catecholamine and nucleotide synthesis, and branched-chain amino acids. Higher resting arginine bioavailability predicted more favorable exercise hemodynamics and pressure-flow relationships. Subjects with more severe PAH augmented arginine bioavailability with exercise to a greater extent than subjects with less severe PAH. We identified relationships between kynurenine pathway metabolism and impaired ventriculo-arterial coupling, worse RV diastolic function, lower RV contractility, diminished RV contractility with exercise, and RV dilation with exercise. Metabolite profiles outperformed NT-proBNP in modeling RV contractility, diastolic function, and exercise performance. Specific metabolite profiles correspond to RV functional measurements only obtainable via invasive pressure-volume loop analysis and predict RV responses to exercise. Metabolic profiling may inform discovery of RV functional biomarkers.NEW & NOTEWORTHY In this cohort of patients with pulmonary arterial hypertension (PAH), we investigate metabolomic associations with comprehensive right ventricular (RV) functional measurements derived from multibeat RV pressure-volume loop analysis. Our results show that tryptophan metabolism, particularly the kynurenine pathway, is linked to intrinsic RV function and PAH pathobiology. Findings also highlight the importance of arginine bioavailability in the cardiopulmonary system's response to exercise stress. Metabolite profiles selected via unbiased analysis outperformed N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) in predicting load-independent measures of RV function at rest and cardiopulmonary system performance under stress. Overall, this work suggests the potential for select metabolites to function as disease-specific biomarkers, offers insights into PAH pathobiology, and informs discovery of potentially targetable RV-centric pathways.

Veno-Pulmonary Arterial Extracorporeal Membrane Oxygenation in Severe Acute Respiratory Distress Syndrome: Should We Consider Mechanical Support of the Pulmonary Circulation From the Outset?

Veno-Pulmonary Arterial Extracorporeal Membrane Oxygenation in Severe Acute Respiratory Distress Syndrome: Should We Consider Mechanical Support of the Pulmonary Circulation From the Outset?

An Update on the Diagnosis and Management of Acute Right Heart Failure.

Right ventricular (RV) dysfunction and resultant acute right heart failure (ARHF) is a rapidly growing field of interest, driven by increasing appreciation of its contribution to heart failure morbidity and mortality. Understanding of ARHF pathophysiology has advanced dramatically over recent years and can be broadly described as RV dysfunction related to acute changes in RV afterload, contractility, preload, or left ventricular dysfunction. There are several diagnostic clinical signs and symptoms as well as imaging and hemodynamic assessments that can provide insight into the degree of RV dysfunction. Medical management is tailored to the different causative pathologies, and in cases of severe or end-stage dysfunction, mechanical circulatory support can be utilized. In this review, we describe the pathophysiology of ARHF, how its diagnosis is established by clinical signs and symptoms and imaging findings, and provide an overview of treatment options, both medical and mechanical.

Right Ventricular Function During Exercise After Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension.

Background Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension improves resting hemodynamics and right ventricular (RV) function. Because exercise tolerance frequently remains impaired, RV function may not have completely normalized after PEA. Therefore, we performed a detailed invasive hemodynamic study to investigate the effect of PEA on RV function during exercise. Methods and Results In this prospective study, all consenting patients with chronic thromboembolic pulmonary hypertension eligible for surgery and able to perform cycle ergometry underwent cardiac magnetic resonance imaging, a maximal cardiopulmonary exercise test, and a submaximal invasive cardiopulmonary exercise test before and 6 months after PEA. Hemodynamic assessment and analysis of RV pressure curves using the single-beat method was used to determine load-independent RV contractility (end systolic elastance), RV afterload (arterial elastance), RV-arterial coupling (end systolic elastance-arterial elastance), and stroke volume both at rest and during exercise. RV rest-to-exercise responses were compared before and after PEA using 2-way repeated-measures analysis of variance with Bonferroni post hoc correction. A total of 19 patients with chronic thromboembolic pulmonary hypertension completed the entire study protocol. Resting hemodynamics improved significantly after PEA. The RV exertional stroke volume response improved 6 months after PEA (79±32 at rest versus 102±28 mL during exercise; P<0.01). Although RV afterload (arterial elastance) increased during exercise, RV contractility (end systolic elastance) did not change during exercise either before (0.43 [0.32-0.58] mm Hg/mL versus 0.45 [0.22-0.65] mm Hg/mL; P=0.6) or after PEA (0.32 [0.23-0.40] mm Hg/mL versus 0.28 [0.19-0.44] mm Hg/mL; P=0.7). In addition, mean pulmonary artery pressure-cardiac output and end systolic elastance-arterial elastance slopes remained unchanged after PEA. Conclusions The exertional RV stroke volume response improves significantly after PEA for chronic thromboembolic pulmonary hypertension despite a persistently abnormal afterload and absence of an RV contractile reserve. This may suggest that at mildly elevated pulmonary pressures, stroke volume is less dependent on RV contractility and afterload and is primarily determined by venous return and conduit function.