The importance of incorporating ventricular-ventricular interaction (VVI) in the study of pulmonary hypertension

Ventricular ventricular interaction (VVI) affects blood volume and pressure in the right and left ventricles of the heart due to the location and balance of forces on the septal wall separating the ventricles. In healthy patients, the pressure of the left ventricle is considerably higher than the right, resulting in a septal wall that bows into the right ventricle. However, in patients with pulmonary hypertension, the pressure in the right ventricle increases significantly to a point where the pressure is similar to or surpasses that of the left ventricle during portions of the cardiac cycle. For these patients, the septal wall deviates towards the left ventricle, impacting its function. It is possible to study this effect using mathematical modeling, but existing models are nonlinear, leading to a system of algebraic differential equations that can be challenging to solve in patient-specific optimizations of clinical data. This study demonstrates that a simplified linearized model is sufficient to account for the effect of VVI and that, as expected, the impact is significantly more pronounced in patients with pulmonary hypertension.

Baroreflex dynamics during the rest to exercise transient in acute normobaric hypoxia in humans

PURPOSE

We hypothesised that during a rest-to-exercise transient in hypoxia (H), compared to normoxia (N), (i) the initial baroreflex sensitivity (BRS) decrease would be slower and (ii) the fast heart rate (HR) and cardiac output (CO) response would have smaller amplitude (A1) due to lower vagal activity in H than N.

METHODS

Ten participants performed three rest-to-50 W exercise transients on a cycle-ergometer in N (ambient air) and three in H (inspired fraction of O2 = 0.11). R-to-R interval (RRi, by electrocardiography) and blood pressure profile (by photo-plethysmography) were recorded non-invasively. Analysis of the latter provided mean arterial pressure (MAP) and stroke volume (SV). CO = HR·SV. BRS was calculated by modified sequence method.

RESULTS

Upon exercise onset in N, MAP fell to a minimum (MAPmin) then recovered. BRS decreased immediately from 14.7 ± 3.6 at rest to 7.0 ± 3.0 ms mmHg-1 at 50 W (p < 0.01). The first BRS sequence detected at 50 W was 8.9 ± 4.8 ms mmHg-1 (p < 0.05 vs. rest). In H, MAP showed several oscillations until reaching a new steady state. BRS decreased rapidly from 10.6 ± 2.8 at rest to 2.9 ± 1.5 ms mmHg-1 at 50 W (p < 0.01), as the first BRS sequence at 50 W was 5.8 ± 2.6 ms mmHg-1 (p < 0.01 vs. rest). CO-A1 was 2.96 ± 1.51 and 2.31 ± 0.94 l min-1 in N and H, respectively (p = 0.06). HR-A1 was 7.7 ± 4.6 and 7.1 ± 5.9 min-1 in N and H, respectively (p = 0.81).

CONCLUSION

The immediate BRS decrease in H, coupled with similar rapid HR and CO responses, is compatible with a withdrawal of residual vagal activity in H associated with increased sympathetic drive.

Pathophysiology of the right ventricle and its pulmonary vascular interaction

The right ventricle and its stress response is perhaps the most important arbiter of survival in patients with pulmonary hypertension of many causes. The physiology of the cardiopulmonary unit and definition of right heart failure proposed in the 2018 World Symposium on Pulmonary Hypertension have proven useful constructs in subsequent years. Here, we review updated knowledge of basic mechanisms that drive right ventricular function in health and disease, and which may be useful for therapeutic intervention in the future. We further contextualise new knowledge on assessment of right ventricular function with a focus on metrics readily available to clinicians and updated understanding of the roles of the right atrium and tricuspid regurgitation. Typical right ventricular phenotypes in relevant forms of pulmonary vascular disease are reviewed and recent studies of pharmacological interventions on chronic right ventricular failure are discussed. Finally, unanswered questions and future directions are proposed.

Biventricular finite element modeling of the fetal heart in health and during critical aortic stenosis

Finite Element simulations are a robust way of investigating cardiac biomechanics. To date, it has only been performed with the left ventricle (LV) alone for fetal hearts, even though results are likely different with biventricular (BiV) simulations. In this research, we conduct BiV simulations of the fetal heart based on 4D echocardiography images to show that it can capture the biomechanics of the normal healthy fetal heart, as well as those of fetal aortic stenosis better than the LV alone simulations. We found that performing LV alone simulations resulted in overestimation of LV stresses and pressures, compared to BiV simulations. Interestingly, inserting a compliance between the LV and right ventricle (RV) in the lumped parameter model of the LV only simulation effectively resolved these overestimations, demonstrating that the septum could be considered to play a LV-RV pressure communication role. However, stresses and strains spatial patterns remained altered from BiV simulations after the addition of the compliance. The BiV simulations corroborated previous studies in showing disease effects on the LV, where fetal aortic stenosis (AS) drastically elevated LV pressures and reduced strains and stroke volumes, which were moderated down with the addition of mitral regurgitation (MR). However, BiV simulations enabled an evaluation of the RV as well, where we observed that effects of the AS and MR on pressures and stroke volumes were generally much smaller and less consistent. The BiV simulations also enabled investigations of septal dynamics, which showed a rightward shift with AS, and partial restoration with MR. Interestingly, AS tended to enhance RV stroke volume, but MR moderated that down.

Congenital diaphragmatic hernia-associated pulmonary hypertension

Congenital diaphragmatic hernia (CDH) is characterized by a developmental insult which compromises cardiopulmonary embryology and results in a diaphragmatic defect, allowing abdominal organs to herniate into the hemithorax. Among the significant pathophysiologic components of this condition is pulmonary hypertension (PH), alongside pulmonary hypoplasia and cardiac dysfunction. Fetal pulmonary vascular development coincides with lung development, with the pulmonary vasculature evolving alongside lung maturation. However, in CDH, this embryologic development is impaired which, in conjunction with external compression, stifle pulmonary vascular maturation, leading to reduced lung density, increased muscularization of the pulmonary vasculature, abnormal vascular responsiveness, and altered molecular signaling, all contributing to pulmonary arterial hypertension. Understanding CDH-associated PH (CDH-PH) is crucial for development of novel approaches and effective management due to its significant impact on morbidity and mortality. Antenatal and postnatal diagnostic methods aid in CDH risk stratification and, specifically, pulmonary hypertension, including fetal imaging and gas exchange assessments. Management strategies include lung protective ventilation, fluid optimization, pharmacotherapies including pulmonary vasodilators and hemodynamic support, and extracorporeal life support (ECLS) for refractory cases. Longitudinal re-evaluation is an important consideration due to the complexity and dynamic nature of CDH cardiopulmonary physiology. Emerging therapies such as fetal endoscopic tracheal occlusion and pharmacological interventions targeting key CDH pathophysiological mechanisms show promise but require further investigation. The complexity of CDH-PH underscores the importance of a multidisciplinary approach for optimal patient care and improved outcomes.

Cardiac function in congenital diaphragmatic hernia

Cardiac function is known to play critical role in the pathophysiological progression and ultimate clinical outcome of patients with congenital diaphragmatic hernia (CDH). While often anatomically normal, the fetal and neonatal heart in CDH can suffer from both right and left ventricular dysfunction. Here we explore the abnormal fetal heart, early postnatal right and left ventricular dysfunction, the interplay between cardiac dysfunction and pulmonary hypertension, evaluation and echocardiographic assessment of the heart, and therapeutic strategies for managing and supporting the pathophysiologic heart and CDH. Further, we take a common clinical scenario and provide clinically relevant guidance for the diagnosis and management of this complex process.

Successful pharmaco-invasive approach using a lower alteplase dose and VA-ECMO support in high-risk pulmonary embolism: case report

Despite the elevated mortality rates associated with high-risk pulmonary embolism (PE), this condition remains understudied. Data regarding the effectiveness and safety of invasive therapies such as venoarterial extracorporeal membrane oxygenation (VA-ECMO) in this patient population remains controversial. Here, we present the case of a 61-year-old male with high-risk PE associated with refractory cardiac arrest and cardiogenic shock who underwent a combination of extracorporeal cardiopulmonary resuscitation with VA-ECMO and pharmaco-invasive therapy (mechanical thrombi fragmentation plus lower alteplase dose), resulting in successful pulmonary reperfusion. After a prolonged in-hospital stay, the patient was discharged in stable condition.

Utility of the novel fetal heart quantification (fetal HQ) technique in diagnosing ventricular interdependence and biventricular dysfunction in a case of prenatally diagnosed Uhl's anomaly

Uhl's anomaly is characterized by complete or partial absence of right ventricular myocardium. We describe a case of prenatally diagnosed Uhl's anomaly with biventricular dysfunction which was quantified with speckle tracking echocardiography using a novel fetal heart quantification (fetal HQ) technique.

Ultrasound unveiling: Decoding venous congestion in heart failure for precision management of fluid status

This editorial discusses the manuscript by Di Maria et al, published in the recent issue of the World Journal of Cardiology. We here focus on the still elusive pathophysiological mechanisms underlying cardio-renal syndrome (CRS), despite its high prevalence and the substantial worsening of both kidney function and heart failure. While the measure of right atrial pressure through right cardiac catheterization remains the most accurate albeit invasive and costly procedure, integrating bedside ultrasound into diagnostic protocols may substantially enhance the staging of venous congestion and guide therapeutic decisions. In particular, with the assessment of Doppler patterns across multiple venous districts, the Venous Excess Ultrasound (VExUS) score improves the management of fluid overload and provides insight into the underlying factors contributing to cardio-renal interactions. Integrating specific echocardiographic parameters, particularly those concerning the right heart, may thus improve the VExUS score sensitivity, offering perspective into the nuanced comprehension of cardio-renal dynamics. A multidisciplinary approach that consistently incorporates the use of ultrasound is emerging as a promising advance in the understanding and management of CRS.

Mechanical Preload Reduction: Harnessing a Cornerstone of Heart Failure Management to Improve Clinical Outcomes

Decongestion is a cornerstone therapeutic goal for those presenting with decompensated heart failure. Current approaches to clinical decongestion include reducing cardiac preload, which is typically limited to diuretics and hemofiltration. Several new technologies designed to mechanically reduce cardiac preload are in development. In this review, we discuss the pathophysiology of decompensated heart failure; the central role of targeting cardiac preload; emerging mechanical preload reduction technologies; and potential application of these devices.

Role of Left Ventricular Dysfunction in Systemic Sclerosis-Related Pulmonary Hypertension

BACKGROUND

In systemic sclerosis (SSc), pulmonary hypertension remains a significant cause of morbidity and mortality. Although conventionally classified as group 1 pulmonary arterial hypertension, systemic sclerosis-related pulmonary hypertension (SSc-PH) is a heterogeneous disease. The contribution of left-sided cardiac disease in SSc-PH remains poorly understood.

RESEARCH QUESTION

How often does left ventricular (LV) dysfunction occur in SSc among patients undergoing right heart catheterization and how does coexistent LV dysfunction with SSc-PH affect all-cause mortality in this patient population?

STUDY DESIGN AND METHODS

We conducted a retrospective, observational study of 165 patients with SSc who underwent both echocardiography and right heart catheterization. LV dysfunction was identified using LV global longitudinal strain (GLS) on speckle-tracking echocardiography based on a defined threshold of > -18%. SSc-PH was defined by a mean pulmonary artery pressure > 20 mmHg.

RESULTS

Among patients with SSc who have undergone right heart catheterization, LV dysfunction occurred in 74.2% with SSc-PH and 51.2% without SSc-PH. The median survival of patients with SSc-PH and LV dysfunction was 67.9 (95% CI, 38.3-102.0) months, with a hazard ratio of 12.64 (95% CI, 1.73-92.60) for all-cause mortality when adjusted for age, sex, SSc disease duration, and FVC compared with patients with SSc without pulmonary hypertension with normal LV function.

INTERPRETATION

LV dysfunction is common in SSc-PH. Patients with SSc-PH and LV dysfunction by LV GLS have increased all-cause mortality. This suggests that LV GLS may be helpful in identifying underlying LV dysfunction and in risk assessment of patients with SSc-PH.

Risk Stratification Using Right Ventricular Longitudinal Strain Ratio Derived from 13N-Ammonia PET in Patients with Ischemic Heart Disease

Purpose To investigate whether right ventricular (RV) myocardial strain ratio (RVMSR) assessed using nitrogen 13 ammonia (13N-NH3) PET can predict cardiovascular events in patients with ischemic heart disease (IHD). Materials and Methods This retrospective study included 480 consecutive patients (mean age, 66 years ± 12 [SD]; 334 males and 146 females) with IHD who underwent 13N-NH3 PET. RVMSR was defined as the ratio of RV strain during stress to that at rest. The primary end point was major adverse cardiac events (MACEs), defined as cardiac death or heart failure hospitalization. The ability of RVMSR to predict MACE was assessed using receiver operating characteristic (ROC) curve and Kaplan-Meier analyses. Cox proportional hazards regression analysis was used to calculate hazard ratios (HRs) with 95% CIs. Results ROC curve analysis identified a sensitivity and specificity of 84% and 82%, respectively, for predicting MACE from RVMSR. Patients with reduced RVMSR (<110.2) displayed a significantly higher rate of MACE than those with a preserved RVMSR (34 of 240 vs four of 240; P < .001). Cox proportional hazards regression analysis of imaging parameters, including myocardial flow reserve, indicated that RVMSR was an independent predictor of MACE (HR, 0.94 [95% CI: 0.92, 0.97]; P < .001). Conclusion RVMSR was an independent predictor of MACE and has potential to aid in the risk stratification of patients with IHD. Keywords: Right Ventricular Myocardial Strain Ratio, Myocardial Flow Reserve, Ischemic Heart Disease, 13N-Ammonia Positron Emission Tomography Supplemental material is available for this article. © RSNA, 2024.

Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with β (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

"Heart of the Matter": Cardiac Dysfunction in Congenital Diaphragmatic Hernia

Despite advances in caring for neonates with congenital diaphragmatic hernia (CDH), mortality and morbidity continues to be high. Additionally, the pathophysiology of cardiac dysfunction in this condition is poorly understood. Postnatal cardiac dysfunction in neonates with CDH may be multifactorial with origins in fetal life. Mechanical obstruction, competition from herniated abdominal organs into thoracic cavity combined with redirection of ductus venosus flow away from patent foramen ovale leading to smaller left-sided structures may be a contributing factor. This shunting decreases left atrial and left ventricular blood volume, which may result in altered micro- and macrovascular aberrations affecting cardiac development in the prenatal period. Direct mass effect from herniated intra-abdominal contents restricting cardiac growth and/or reduced left ventricular preload may contribute independently to left ventricular dysfunction in the absence of right ventricular dysfunction and or pulmonary hypertension. With variable clinical phenotypes of cardiac dysfunction, pulmonary hypertension, and respiratory failure in patients with CDH, there is increased need for individualized diagnosis and tailored therapy. Routine use of therapy such as inhaled nitric oxide and sildenafil that induces significant pulmonary vasodilation may be detrimental in left ventricle dysfunction, whereas in a patient with pure right ventricle dysfunction, they may be beneficial. Targeted functional echocardiography serves as a real-time tool for defining the pathophysiology and aids optimization of vasoactive therapy in affected neonates. KEY POINTS: · Cardiac dysfunction in neonates with CDH is multifactorial.. · Postnatal cardiac dysfunction in patients with CDH has its origins in fetal life.. · Right ventricular dysfunction contributes to systemic hypotension.. · Left ventricular dysfunction contributes to systemic hypotension.. · Supportive therapy should be tailored to clinical phenotype..

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

Complex Heart-Lung Ventilator Emergencies in the CICU

This review aims to enhance the comprehension and management of cardiopulmonary interactions in critically ill patients with cardiovascular disease undergoing mechanical ventilation. Highlighting the significance of maintaining a delicate balance, this article emphasizes the crucial role of adjusting ventilation parameters based on both invasive and noninvasive monitoring. It provides recommendations for the induction and liberation from mechanical ventilation. Special attention is given to the identification of auto-PEEP (positive end-expiratory pressure) and other situations that may impact hemodynamics and patients' outcomes.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome. The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD. This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax). In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20-2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07-2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis. Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

How Would I Treat My Own Chronic Thromboembolic Pulmonary Hypertension in the Perioperative Period?

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an incomplete resolution of acute pulmonary embolism, leading to occlusive organized thrombi, vascular remodeling, and associated microvasculopathy with pulmonary hypertension (PH). A definitive CTEPH diagnosis requires PH confirmation by right-heart catheterization and evidence of chronic thromboembolic pulmonary disease on imaging studies. Surgical removal of the organized fibrotic material by pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest represents the treatment of choice. One-third of patients with CTEPH are not deemed suitable for surgical treatment, and medical therapy or interventional balloon pulmonary angioplasty presents alternative treatment options. Pulmonary endarterectomy in patients with technically operable disease significantly improves symptoms, functional capacity, hemodynamics, and quality of life. Perioperative mortality is <2.5% in expert centers where a CTEPH multidisciplinary team optimizes patient selection and ensures the best preoperative optimization according to individualized risk assessment. Despite adequate pulmonary artery clearance, patients might be prone to perioperative complications, such as right ventricular maladaptation, airway bleeding, or pulmonary reperfusion injury. These complications can be treated conventionally, but extracorporeal membrane oxygenation has been included in their management recently. Patients with residual PH post-PEA should be considered for medical or percutaneous interventional therapy.

Effect of left bundle branch pacing on right ventricular function: A 3-dimensional echocardiography study

BACKGROUND

The effect of left bundle branch pacing (LBBP) on right ventricular (RV) function is not well known, and there is conflicting evidence regarding whether cardiac resynchronization therapy improves RV function.

OBJECTIVES

The study aimed to investigate the effect of LBBP on RV function and to evaluate the response of RV dysfunction (RVD) to LBBP.

METHODS

Sixty-five LBBP candidates were prospectively included in the study and underwent echocardiography at baseline and 6-month follow-up. LBBP response was left ventricular (LV) reverse remodeling, defined as a reduction in LV end-systolic volume of ≥15% at follow-up.

RESULTS

Patients were assigned to 2 subgroups on the basis of 3-dimensional echocardiography-derived RV ejection fraction (EF) before LBBP implantation: 30 patients (46%) in the no RVD group and 35 patients (54%) in the RVD group. The RVD group was characterized by higher N-terminal pro-brain natriuretic peptide levels, New York Heart Association functional class, and larger LV/RV size. LBBP induced a significant reduction in QRS duration, LV size, and improvement in LVEF and mechanical dyssynchrony in both the no RVD and RVD groups, and a significant improvement in RV volumes and RVEF in the RVD group (all P<.01). LBBP resulted in a similar percentage reduction in QRS duration, LV dimensions, LV volumes, and percentage improvement in LVEF in RVD and no RVD groups (all P＞.05). LV reverse remodeling (29 of 35 patients vs 27 of 30 patients; P = .323) in the RVD group was similar to that in the no RVD group after LBBP.

CONCLUSION

LBBP induces excellent electrical and mechanical resynchronization, with a significant improvement in RV volumes and function. RVD did not diminish the beneficial effects on LV reverse remodeling after LBBP.

Implications of tricuspid regurgitation and right ventricular volume overload in patients with heart failure with preserved ejection fraction

AIMS

The aim of this study was to assess the pathophysiological implications of severe tricuspid regurgitation (TR) in patients with heart failure with preserved ejection fraction (HFpEF) by using tricuspid transcatheter edge-to-edge repair (T-TEER) as a model of right ventricular (RV) volume overload relief.

METHODS AND RESULTS

This prospective interventional single arm trial (NCT04782908) included patients with invasively diagnosed HFpEF. The following parameters were prospectively assessed before and after T-TEER: left ventricular (LV) diastolic properties by invasive pressure-volume loop recordings; biventricular time-volume curves and function as well as septal curvature by cardiac magnetic resonance imaging; strain analyses for timing of septal motion. Overall, 20 patients (median age 78, interquartile range [IQR] 72-83 years, 65% female) were included. T-TEER reduced TR by a median of 2 (of 5) grades (IQR 2-1). T-TEER increased LV stroke volume and LV end-diastolic volume (LVEDV) (p < 0.001), without increasing LV end-diastolic pressure (LVEDP) (p = 0.094), consequently diastolic function improved with a reduction in LVEDP/LVEDV (p = 0.001) and a rightward shift of the end-diastolic pressure-volume relationship. The increase in LVEDV correlated with a decrease in RV end-diastolic volume (p < 0.001) and LV transmural pressure increased (p = 0.028). Secondary to a decrease in early RV filling, improvements in early LV filling were observed, correlating with an alleviation of leftwards bowing of the septum (p < 0.01, respectively).

CONCLUSION

Diastolic LV properties in patients with HFpEF and severe TR are importantly determined by ventricular interaction in the setting of RV volume overload. T-TEER reduces RV volume overload and improves biventricular interaction and physiology.

How Right is the Right Ventricle in Predicting Cardiac Mortality in Cardiac Failure: A 6-year Prospective Cohort Study

Aim

Two-dimensional speckle tracking echocardiography (2D-STE) and three-dimensional echocardiography (3DE) may overcome many limitations of the conventional 2D echocardiography (2DE) in assessing right ventricular (RV) function. We sought to determine whether characteristics of the right atrium and right ventricle as measured by 2D-STE and 3DE are associated with cardiac mortality in patients with ischemic heart failure, over a 6-year follow-up.

Materials and Methods

The inclusion criteria were ischemic cardiomyopathy with left ventricular ejection fraction of <40% diagnosed using standard 2DE, 2D-STE, and 3DE examination. Patients were followed for 6 years, and cardiac mortality was recorded.

Results

The study sample comprised a total of 54 participants. During the period of follow-up, 24% (13/54) died. The 2DE models showed that being older, having a higher body mass index (BMI), having higher systolic pulmonary artery pressure (SPAP), and a lower RV global longitudinal strain were associated with cardiac mortality in our cohort after 6-year follow-up. Finally, the 3DE models showed that in addition to being older, having higher BMI, having a higher SPAP baseline, lower baseline 3DE RV stroke volume, and larger 3DE RV end-diastolic volume and 3DE RV end-systolic volume were associated with cardiac mortality over 6-year follow-up.

Conclusion

This study provides evidence that RV dysfunction as seen on 2D-STE and 3DE could be associated with increased risk of cardiac-related mortality in patients with heart failure over 6 years.

Diagnosis, management and long term cardiovascular outcomes of phenotypic profiles in pulmonary hypertension associated with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a developmental defect of the diaphragm resulting in herniation of viscera into the chest. This condition is characterized by pulmonary hypoplasia, pulmonary hypertension (PH) and cardiac ventricular dysfunction. PH is a key component of the pathophysiology of CDH in neonates and contributes to morbidity and mortality. Traditionally, PH associated with CDH (CDH-PH) is thought to be secondary to increased pulmonary arterial resistance and vasoreactivity resulting from pulmonary hypoplasia. Additionally, there is increasing recognition of associated left ventricular hypoplasia, dysfunction and elevated end diastolic pressure resulting in pulmonary venous hypertension in infants with CDH. Thus, hemodynamic management of these infants is complex and cautious use of pulmonary vasodilators such as inhaled nitric oxide (iNO) is warranted. We aim to provide an overview of different phenotypic profiles of CDH associated PH and potential management options based on current evidence and pathophysiology.

Myocardial fibrosis in right heart dysfunction

Cardiac fibrosis, associated with right heart dysfunction, results in significant morbidity and mortality. Stimulated by various cellular and humoral stimuli, cardiac fibroblasts, macrophages, CD4+ and CD8+ T cells, mast and endothelial cells promote fibrogenesis directly and indirectly by synthesizing numerous profibrotic factors. Several systems, including the transforming growth factor-beta and the renin-angiotensin system, produce type I and III collagen, fibronectin and α-smooth muscle actin, thus modifying the extracellular matrix. Although magnetic resonance imaging with gadolinium enhancement remains the gold standard, the use of circulating biomarkers represents an inexpensive and attractive means to facilitate detection and monitor cardiovascular fibrosis. This review explores the use of protein and nucleic acid (miRNAs) markers to better understand underlying pathophysiology as well as their role in the development of therapeutics to inhibit and potentially reverse cardiac fibrosis.

Prognostic value of right ventricular free wall strain in patients with sepsis

Background

Right ventricular systolic dysfunction (RVSD) in patients with sepsis is an area of growing interest, but its prognostic significance remains unclear and additional tools are needed to improve our understanding. Right ventricular free wall strain (RV-FWS) is a relatively new parameter to assess RV function. This study aimed to investigate the potential correlation between impaired RV-FWS and prognostic outcomes in patients with sepsis.

Methods

We prospectively assessed right ventricular function in patients with sepsis within the initial 24 h of their hospital admission. RV-FWS, right ventricular global strain (RV-GS), fractional area change (FAC), and tricuspid annular plane systolic excursion (TAPSE) were examined. RVSD was defined as impaired RV-FWS. Moreover, the association between RVSD and 30-day mortality rate was assessed.

Results

This study included 89 patients. Among them, 27 (30.3%) succumbed to their illness within 30 days. The nonsurviving patients demonstrated significantly lower absolute RV-FWS (-19.7% ± 2.4% vs. -21.1% ± 2.1%, P = 0.008) and RV-GS (-17.7% ± 1.2% vs. -18.4% ± 1.4%, P = 0.032) values than the surviving patients. However, TAPSE and FAC values were not significantly different between the two groups. The optimal cutoff values for RV-FWS, RV-GS, FAC, and TAPSE were -19.0%, -17.9%, 36.5%, and 1.55 cm, respectively. Kaplan-Meier survival curves revealed that patients with impaired RV-FWS and RV-GS demonstrated lower 30-day survival rates, and the predictive performance of RV-FWS (hazard ratio [HR]: 3.97, 95% confidence interval [CI]: 1.85-8.51, P < 0.001) was slightly higher than FAC and TAPSE. However, multivariable Cox regression analysis revealed no association between impaired RV-FWS and mortality outcomes (HR: 1.85, 95% CI: 0.56-6.14, P = 0.316).

Conclusions

Impaired RV-FWS is not associated with short-term mortality outcomes, and RV strain imaging is of limited value in assessing the prognosis of sepsis.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair

BACKGROUND

Recently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it's not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually.

CASE PRESENTATION

We report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms.

CONCLUSION

In a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

Acute changes in cardiac dimensions, function, and longitudinal mechanics in healthy individuals with and without high-altitude induced pulmonary hypertension at 4559 m

BACKGROUND

High-altitude pulmonary hypertension (HAPH) has a prevalence of approximately 10%. Changes in cardiac morphology and function at high altitude, compared to a population that does not develop HAPH are scarce.

METHODS

Four hundred twenty-one subjects were screened in a hypoxic chamber inspiring a FiO2  = 12% for 2 h. In 33 subjects an exaggerated increase in systolic pulmonary artery pressure (sPAP) could be confirmed in two independent measurements. Twenty nine of these, and further 24 matched subjects without sPAP increase were examined at 4559 m by Doppler echocardiography including global longitudinal strain (GLS).

RESULTS

SPAP increase was higher in HAPH subjects (∆ = 10.2 vs. ∆ = 32.0 mm Hg, p < .001). LV eccentricity index (∆ = .15 vs. ∆ = .31, p = .009) increased more in HAPH. D-shaped LV (0 [0%] vs. 30 [93.8%], p = .00001) could be observed only in the HAPH group, and only in those with a sPAP ≥50 mm Hg. LV-EF (∆ = 4.5 vs. ∆ = 6.7%, p = .24) increased in both groups. LV-GLS (∆ = 1.2 vs. ∆ = 1.1 -%, p = .60) increased slightly. RV end-diastolic (∆ = 2.20 vs. ∆ = 2.7 cm2 , p = .36) and end-systolic area (∆ = 2.1 vs. ∆ = 2.7 cm2 , p = .39), as well as RA end-systolic area index (∆ = -.9 vs. ∆ = .3 cm2 /m2 , p = .01) increased, RV-FAC (∆ = -2.9 vs. ∆ = -4.7%, p = .43) decreased, this was more pronounced in HAPH, RV-GLS (∆ = 1.6 vs. ∆ = -.7 -%, p = .17) showed marginal changes.

CONCLUSIONS

LV and LA dimensions decrease and left ventricular function increases at high-altitude in subjects with and without HAPH. RV and RA dimensions increase, and RV longitudinal strain increases or remains unchanged in subjects with HAPH. Changes are negligible in those without HAPH.

Clinical-imaging-pathological correlation in pulmonary hypertension associated with left heart disease

Pulmonary hypertension (PH) is highly prevalent in patients with left heart disease (LHD) and negatively impacts prognosis. The most common causes of PH associated with LHD (PH-LHD) are left heart failure and valvular heart disease. In LHD, passive backward transmission of increased left-sided filling pressures leads to isolated post-capillary PH. Additional pulmonary vasoconstriction and remodelling lead to a higher vascular load and combined pre- and post-capillary PH. The increased afterload leads to right ventricular dysfunction and failure. Multimodality imaging of the heart plays a central role in the diagnostic work-up and follow-up of patients with PH-LHD. Echocardiography provides information about the estimated pulmonary artery pressure, morphology and function of the left and right side of the heart, and valvular abnormalities. Cardiac magnetic resonance imaging is the gold standard for volumetric measurements and provides myocardial tissue characterisation. Computed tomography of the thorax may show general features of PH and/or LHD and is helpful in excluding other PH causes. Histopathology reveals a spectrum of pre- and post-capillary vasculopathy, including intimal fibrosis, media smooth muscle cell hyperplasia, adventitial fibrosis and capillary congestion. In this paper, we provide an overview of clinical, imaging and histopathological findings in PH-LHD based on three clinical cases.

The nitric oxide-soluble guanylate cyclase-cGMP pathway in pulmonary hypertension: from PDE5 to soluble guanylate cyclase

The nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway plays a key role in the pathogenesis of pulmonary hypertension (PH). Targeted treatments include phosphodiesterase type 5 inhibitors (PDE5i) and sGC stimulators. The sGC stimulator riociguat is approved for the treatment of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). sGC stimulators have a dual mechanism of action, enhancing the sGC response to endogenous NO and directly stimulating sGC, independent of NO. This increase in cGMP production via a dual mechanism differs from PDE5i, which protects cGMP from degradation by PDE5, rather than increasing its production. sGC stimulators may therefore have the potential to increase cGMP levels under conditions of NO depletion that could limit the effectiveness of PDE5i. Such differences in mode of action between sGC stimulators and PDE5i could lead to differences in treatment efficacy between the classes. In addition to vascular effects, sGC stimulators have the potential to reduce inflammation, angiogenesis, fibrosis and right ventricular hypertrophy and remodelling. In this review we describe the evolution of treatments targeting the NO-sGC-cGMP pathway, with a focus on PH.

Post-implantation CMR imaging to study biventricular pacing effects on the right ventricle in left bundle branch block patients

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients with left ventricular dysfunction and a left bundle branch block. However, its impact on right ventricular (RV) function remains uncertain. This cardiac magnetic resonance imaging study found that CRT did not improve RV volumes and function, and CRT-off during follow-up had an immediate detrimental effect on the RV, which may suggest potential unfavorable RV remodeling with RV pacing during CRT.

Utility of Cardiopulmonary Exercise Testing in Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a disease defined by airflow obstruction with a high morbidity and mortality and significant economic burden. Although pulmonary function testing is the cornerstone in diagnosis of COPD, it cannot fully characterize disease severity or cause of dyspnea because of disease heterogeneity and variable related and comorbid conditions affecting cardiac, vascular, and musculoskeletal systems. Cardiopulmonary exercise testing (CPET) is a valuable tool for assessing physical function in a wide range of clinical conditions, including COPD. Familiarity with measurements made during CPET and its potential to aid in clinical decision-making related to COPD can thus be useful to clinicians caring for this population. This review highlights pulmonary and extrapulmonary impairments that can contribute to exercise limitation in COPD. Key elements of CPET are identified with an emphasis on measurements most relevant to COPD. Finally, clinical applications of CPET demonstrated to be of value in the COPD setting are identified. These include quantifying functional capacity, differentiating among potential causes of symptoms and limitation, prognostication and risk assessment for operative procedures, and guiding exercise prescription.

Perioperative Management in Pulmonary Endarterectomy

Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension (PH), provided lesions are proximal enough in the pulmonary vasculature to be surgically accessible and the patient is well enough to benefit from the operation in the longer term. It is a major cardiothoracic operation, requiring specialized techniques and instruments developed over several decades to access and dissect out the intra-arterial fibrotic material. While in-hospital operative mortality is low (<5%), particularly in high-volume centers, careful perioperative management in the operating theater and intensive care is mandatory to balance ventricular performance, fluid balance, ventilation, and coagulation to avoid or treat complications. Reperfusion pulmonary edema, airway hemorrhage, and right ventricular failure are the most problematic complications, often requiring the use of extracorporeal membrane oxygenation to bridge to recovery. Successful PEA has been shown to improve both morbidity and mortality in large registries, with survival >70% at 10 years. For patients not suitable for PEA or with residual PH after PEA, balloon pulmonary angioplasty and/or PH medical therapy may prove beneficial. Here, we describe the indications for PEA, specific surgical and perioperative strategies, postoperative monitoring and management, and approaches for managing residual PH in the long term.

Management of Acutely Decompensated Pulmonary Hypertension

Pulmonary arterial hypertension is a severe life-threatening condition associated with increased pulmonary vascular resistance and resulting right heart dysfunction. Admission to intensive care unit with acutely decompensated right heart failure is a significant negative prognostic event with a high risk of multisystem organ dysfunction and death. Presentations are heterogenous and may combine signs of both diastolic and systolic dysfunction complicating management. Renal dysfunction is often present, but other organ systems can be involved resulting in findings such as acute hepatic dysfunction or bowel wall congestion and ischemia. The goals of therapy are to rapidly reverse ventriculo-arterial decoupling and reduce right ventricular afterload to prevent progression to refractory or irreversible right heart failure. Triggering events must be investigated for and addressed urgently if identified. Volume status management is critical and both noninvasive and invasive testing can aid in prognostication and guide management, including the use of inotropes and vasopressors. In cases of refractory right heart dysfunction, consideration of urgent lung transplantation and mechanical circulatory support is necessary. These patients should be managed at expert centers in an intensive care setting with a multidisciplinary team of practitioners experienced in the management of right heart dysfunction given the high short- and long-term mortality resulting from acute decompensated right heart failure.

Papillary muscle approximation in chronic ovine functional tricuspid regurgitation

OBJECTIVE

Isolated tricuspid ring annuloplasty remains the surgical standard for functional tricuspid regurgitation repair but offers suboptimal results when right ventricular dilation and remodeling along with papillary muscle displacement is present. Addressing subvalvular remodeling with papillary muscle approximation may improve clinical outcomes.

METHODS

Functional tricuspid regurgitation and biventricular dysfunction were induced in 8 healthy sheep by rapid ventricular pacing (200-240 bpm) for 27 ± 6 days. Subsequently, animals underwent cardiopulmonary bypass for implantation of sonomicrometry crystals on the tricuspid annulus, right ventricle, and papillary muscle tips. Papillary approximation sutures were anchored between anterior-posterior and anterior-septal papillary muscles and externalized through right ventricular free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, sequential papillary muscle approximations were performed. Simultaneous hemodynamic, sonomicrometry, and echocardiographic data were collected at baseline and after each papillary muscle approximation.

RESULTS

With rapid pacing, right ventricular fractional area change decreased from 59 ± 6% to 38 ± 8% (P < .001), whereas tricuspid annulus diameter increased from 2.4 ± 0.3 cm to 3.3 ± 0.6 cm (P = .003). Tricuspid regurgitation (0-4+) increased from +0 ± 0 to +3.3 ± 0.7 (P < .001). Both anterior-posterior and anterior-septal papillary muscle approximation significantly reduced functional tricuspid regurgitation from +3.3 ± 0.7 to +2 ± 0.5 and +1.9 ± 0.6, respectively (P < .001). Reduction of tricuspid insufficiency with both subvalvular interventions was associated with decreased distance of the anterior papillary muscle to the annular centroid.

CONCLUSIONS

Papillary muscle approximations were effective in reducing severe ovine functional tricuspid regurgitation associated with right ventricular dilation and papillary muscle displacement. Further studies are needed to evaluate efficacy of this adjunct to ring annuloplasty in repair of severe functional tricuspid regurgitation.

Transcatheter Treatment for Double-Chambered Right Ventricle in Patient Presenting Severe Chronic Heart Failure

We report a case involving a 9-year-old girl with severe biventricular dysfunction due to anomalous right ventricle muscle bands. After a thorough discussion, she underwent a transcatheter stenting procedure for the double-chambered right ventricle. During her follow-up, she regained biventricular function, while remaining asymptomatic, resulting in complete recovery.

Clinical and functional relevance of right ventricular contraction patterns in pulmonary hypertension

BACKGROUND

The right ventricle has a complex contraction pattern of uncertain clinical relevance. We aimed to assess the relationship between right ventricular (RV) contraction pattern and RV-pulmonary arterial (PA) coupling defined by the gold-standard pressure-volume loop-derived ratio of end-systolic/arterial elastance (Ees/Ea).

METHODS

Prospectively enrolled patients with suspected or confirmed pulmonary hypertension underwent three-dimensional echocardiography, standard right heart catheterization, and RV conductance catheterization. RV-PA uncoupling was categorized as severe (Ees/Ea < 0.8), moderate (Ees/Ea 0.8-1.29), and none/mild (Ees/Ea ≥ 1.3). Clinical severity was determined from hemodynamics using a truncated version of the 2022 European Society of Cardiology/European Respiratory Society risk stratification scheme.

RESULTS

Fifty-three patients were included, 23 with no/mild, 24 with moderate, and 6 with severe uncoupling. Longitudinal shortening was decreased in patients with moderate vs no/mild uncoupling (p <0.001) and intermediate vs low hemodynamic risk (p < 0.001), discriminating low risk from intermediate/high risk with an optimal threshold of 18% (sensitivity 80%, specificity 87%). Anteroposterior shortening was impaired in patients with severe vs moderate uncoupling (p = 0.033), low vs intermediate risk (p = 0.018), and high vs intermediate risk (p = 0.010), discriminating high risk from intermediate/low risk with an optimal threshold of 15% (sensitivity 100%, specificity 83%). Left ventricular (LV) end-diastolic volume was decreased in patients with severe uncoupling (p = 0.035 vs no/mild uncoupling).

CONCLUSIONS

Early RV-PA uncoupling is associated with reduced longitudinal function, whereas advanced RV-PA uncoupling is associated with reduced anteroposterior movement and LV preload, all in a risk-related fashion.

CLINICALTRIALS

GOV: NCT04663217.

Left ventricular underfilling in PAH: A potential indicator for adaptive-to-maladaptive transition

Pulmonary arterial hypertension (PAH) still remains a life-threatening disorder with poor prognosis. The right ventricle (RV) adapts to the increased afterload by a series of prognostically significant morphological and functional changes, the adaptive nature should also be understood in the context of ventricular interdependence. We hypothesized that left ventricle (LV) underfilling could serve as an important imaging marker for identifying maladaptive changes and predicting clinical outcomes in PAH patients. We prospectively enrolled patients with PAH who underwent both cardiac magnetic resonance and right heart catheterization between October 2013 and December 2020. Patients were categorized into four groups based on their LV and RV mass/volume ratio (M/V). LV M/V was stratified using the normal value (0.7 g/mL for males and 0.6 g/mL for females) to identify patients with LV underfilling (M/V ≥ normal value), while RV M/V was stratified based on the median value. The primary endpoint was all-cause mortality, and the composite endpoints included all-cause mortality and heart failure-related readmissions. A total of 190 PAH patients (53 male, mean age 37 years) were included in this study. Patients with LV underfilling exhibited higher NT-proBNP levels, increased RV mass, larger RV but smaller LV, lower right ventricular ejection fraction, and shorter 6-min walking distance. Patients with LV underfilling had a 2.7-fold higher risk of mortality than those without and LV M/V (hazard ratio [per 0.1 g/mL increase]: 1.271, 95% confidence interval: 1.082-1.494, p = 0.004) was also independent predictors of all-cause mortality. Moreover, patients with low LV M/V had a better prognosis regardless of the level of RV M/V. Thus, LV underfilling is an independent predictor of adverse clinical outcomes in patients with PAH, and it could be an important imaging marker for identifying maladaptive changes in these patients.

Computational modeling of ventricular-ventricular interactions suggest a role in clinical conditions involving heart failure

Introduction: The left (LV) and right (RV) ventricles are linked biologically, hemodynamically, and mechanically, a phenomenon known as ventricular interdependence. While LV function has long been known to impact RV function, the reverse is increasingly being realized to have clinical importance. Investigating ventricular interdependence clinically is challenging given the invasive measurements required, including biventricular catheterization, and confounding factors such as comorbidities, volume status, and other aspects of subject variability. Methods: Computational modeling allows investigation of mechanical and hemodynamic interactions in the absence of these confounding factors. Here, we use a threesegment biventricular heart model and simple circulatory system to investigate ventricular interdependence under conditions of systolic and diastolic dysfunction of the LV and RV in the presence of compensatory volume loading. We use the end-diastolic pressure-volume relationship, end-systolic pressure-volume relationship, Frank Starling curves, and cardiac power output as metrics. Results: The results demonstrate that LV systolic and diastolic dysfunction lead to RV compensation as indicated by increases in RV power. Additionally, RV systolic and diastolic dysfunction lead to impaired LV filling, interpretable as LV stiffening especially with volume loading to maintain systemic pressure. Discussion: These results suggest that a subset of patients with intact LV systolic function and diagnosed to have impaired LV diastolic function, categorized as heart failure with preserved ejection fraction (HFpEF), may in fact have primary RV failure. Application of this computational approach to clinical data sets, especially for HFpEF, may lead to improved diagnosis and treatment strategies and consequently improved outcomes.

Right Heart Adaptation to Exercise in Pulmonary Hypertension: An Invasive Hemodynamic Study

BACKGROUND

Right heart failure (RHF) is associated with a dismal prognosis in patients with pulmonary hypertension (PH). Exercise right heart catheterization may unmask right heart maladaptation as a sign of RHF. We sought to (1) define the normal limits of right atrial pressure (RAP) increase during exercise; (2) describe the right heart adaptation to exercise in PH owing to heart failure with preserved ejection fraction (PH-HFpEF) and in pulmonary arterial hypertension (PAH); and (3) identify the factors associated with right heart maladaptation during exercise.

METHODS AND RESULTS

We analyzed rest and exercise right heart catheterization from patients with PH-HFpEF and PAH. Right heart adaptation was described by absolute or cardiac output (CO)-normalized changes of RAP during exercise. Individuals with noncardiac dyspnea (NCD) served to define abnormal RAP responses (>97.5th percentile). Thirty patients with PH-HFpEF, 30 patients with PAH, and 21 patients with NCD were included. PH-HFpEF were older than PAH, with more cardiovascular comorbidities, and a higher prevalence of severe tricuspid regurgitation (P < .05). The upper limit of normal for peak RAP and RAP/CO slope in NCD were >12 mm Hg and ≥1.30 mm Hg/L/min, respectively. PH-HFpEF had higher peak RAP and RAP/CO slope than PAH (20 mm Hg [16-24 mm Hg] vs 12 mm Hg [9-19 mm Hg] and 3.47 mm Hg/L/min [2.02-6.19 mm Hg/L/min] vs 1.90 mm Hg/L/min [1.01-4.29 mm Hg/L/min], P < .05). A higher proportion of PH-HFpEF had RAP/CO slope and peak RAP above normal (P < .001). Estimated stressed blood volume at peak exercise was higher in PH-HFpEF than PAH (P < .05). In the whole PH cohort, the RAP/CO slope was associated with age, the rate of increase in estimated stressed blood volume during exercise, severe tricuspid regurgitation, and right atrial dilation.

CONCLUSIONS

Patients with PH-HFpEF display a steeper increase of RAP during exercise than those with PAH. Preload-mediated mechanisms may play a role in the development of exercise-induced RHF.

Pathophysiology of the right ventricle in health and disease: an update

The contribution of the right ventricle (RV) to cardiac output is negligible in normal resting conditions when pressures in the pulmonary circulation are low. However, the RV becomes relevant in healthy subjects during exercise and definitely so in patients with increased pulmonary artery pressures both at rest and during exercise. The adaptation of RV function to loading rests basically on an increased contractility. This is assessed by RV end-systolic elastance (Ees) to match afterload assessed by arterial elastance (Ea). The system has reserve as the Ees/Ea ratio or its imaging surrogate ejection fraction has to decrease by more than half, before the RV undergoes an increase in dimensions with eventual increase in filling pressures and systemic congestion. RV-arterial uncoupling is accompanied by an increase in diastolic elastance. Measurements of RV systolic function but also of diastolic function predict outcome in any cause pulmonary hypertension and heart failure with or without preserved left ventricular ejection fraction. Pathobiological changes in the overloaded RV include a combination of myocardial fibre hypertrophy, fibrosis and capillary rarefaction, a titin phosphorylation-related displacement of myofibril tension-length relationships to higher pressures, a metabolic shift from mitochondrial free fatty acid oxidation to cytoplasmic glycolysis, toxic lipid accumulation, and activation of apoptotic and inflammatory signalling pathways. Treatment of RV failure rests on the relief of excessive loading.

Ventricular interdependence in critically ill patients: from physiology to bedside

The review focuses on the mechanism of ventricular interdependence, a frequently encountered phenomena, especially in critically ill patients. It is explained by the anatomy of the heart, with two ventricles sharing a common wall, the septum, and nested in an acutely inextensible envelope, the pericardium. In pathological situation, it results in abnormal movements of the interventricular septum driven by respiration, leading to abnormal filling of one or the other ventricle. Ventricular interdependence has several clinical applications and explains some situations of hemodynamic impairment, especially in situations of cardiac tamponade, severe acute asthma, right ventricular (RV) overload, or more simply, in case of positive pressure ventilation with underlying acute pulmonary hypertension. Ventricular interdependence can be monitored with pulmonary arterial catheter or echocardiography. Knowledge of this phenomena has very concrete clinical applications in the management of filling or in the prevention or treatment of RV overload.

Simultaneous venous-arterial Doppler during preload augmentation: illustrating the Doppler Starling curve

Providing intravenous (IV) fluids to a patient with signs or symptoms of hypoperfusion is common. However, evaluating the IV fluid 'dose-response' curve of the heart is elusive. Two patients were studied in the emergency department with a wireless, wearable Doppler ultrasound system. Change in the common carotid arterial and internal jugular Doppler spectrograms were simultaneously obtained as surrogates of left ventricular stroke volume (SV) and central venous pressure (CVP), respectively. Both patients initially had low CVP jugular venous Doppler spectrograms. With preload augmentation, only one patient had arterial Doppler measures indicative of significant SV augmentation (i.e., 'fluid responsive'). The other patient manifested diminishing arterial response, suggesting depressed SV (i.e., 'fluid unresponsive') with evidence of ventricular asynchrony. In this short communication, we describe how a wireless, wearable Doppler ultrasound simultaneously tracks surrogates of cardiac preload and output within a 'Doppler Starling curve' framework; implications for IV fluid dosing are discussed.

Echocardiography Imaging of the Right Ventricle: Focus on Three-Dimensional Echocardiography

Right ventricular function strongly predicts cardiac death and adverse cardiac events in patients with cardiac diseases. However, the accurate right ventricular assessment by two-dimensional echocardiography is limited due to its complex anatomy, shape, and load dependence. Advances in cardiac imaging and three-dimensional echocardiography provided more reliable information on right ventricular volumes and function without geometrical assumptions. Furthermore, the pathophysiology of right ventricular dysfunction and tricuspid regurgitation is frequently connected. Three-dimensional echocardiography allows a more in-depth structural and functional evaluation of the tricuspid valve. Understanding the anatomy and pathophysiology of the right side of the heart may help in diagnosing and managing the disease by using reliable imaging tools. The present review describes the challenging echocardiographic assessment of the right ventricle and tricuspid valve apparatus in clinical practice with a focus on three-dimensional echocardiography.

Pulmonary Hypertension in Left Heart Diseases: Pathophysiology, Hemodynamic Assessment and Therapeutic Management

Pulmonary hypertension (PH) associated with left heart diseases (PH-LHD), also termed group 2 PH, represents the most common form of PH. It develops through the passive backward transmission of elevated left heart pressures in the setting of heart failure, either with preserved (HFpEF) or reduced (HFrEF) ejection fraction, which increases the pulsatile afterload of the right ventricle (RV) by reducing pulmonary artery (PA) compliance. In a subset of patients, progressive remodeling of the pulmonary circulation resulted in a pre-capillary phenotype of PH, with elevated pulmonary vascular resistance (PVR) further increasing the RV afterload, eventually leading to RV-PA uncoupling and RV failure. The primary therapeutic objective in PH-LHD is to reduce left-sided pressures through the appropriate use of diuretics and guideline-directed medical therapies for heart failure. When pulmonary vascular remodeling is established, targeted therapies aiming to reduce PVR are theoretically appealing. So far, such targeted therapies have mostly failed to show significant positive effects in patients with PH-LHD, in contrast to their proven efficacy in other forms of pre-capillary PH. Whether such therapies may benefit some specific subgroups of patients (HFrEF, HFpEF) with specific hemodynamic phenotypes (post- or pre-capillary PH) and various degrees of RV dysfunction still needs to be addressed.

Assessment of Right Ventricular Function-a State of the Art

PURPOSE OF REVIEW

The right ventricle (RV) has a complex geometry and physiology which is distinct from the left. RV dysfunction and failure can be the aftermath of volume- and/or pressure-loading conditions, as well as myocardial and pericardial diseases.

RECENT FINDINGS

Echocardiography, magnetic resonance imaging and right heart catheterisation can assess RV function by using several qualitative and quantitative parameters. In pulmonary hypertension (PH) in particular, RV function can be impaired and is related to survival. An accurate assessment of RV function is crucial for the early diagnosis and management of these patients. This review focuses on the different modalities and indices used for the evaluation of RV function with an emphasis on PH.

Tricuspid Regurgitation: Right Ventricular Volume Versus Pressure Load

PURPOSE OF THE REVIEW

Tricuspid regurgitation is associated with increased mortality in proportion to right ventricular adaptation to increased volume loading and pulmonary artery pressure. We here review recent progress in the understanding of right ventricular adaptation to pre- and after-loading conditions for improved recommendations of tricuspid valve repair.

RECENT FINDINGS

Trans-catheter tricuspid valve repair has made the correction of tricuspid regurgitation more easily available, triggering a need of tighter indications. Several studies have shown the feasibility and relevance to the indications of tricuspid valve repair of imaging of right ventricular ejection fraction measured by magnetic resonance imaging or 3D-echocardiography, and the 2D-echocardiography of the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio combined with invasively determined mean pulmonary artery pressure and pulmonary vascular resistance. Improved definitions of right ventricular failure and pulmonary hypertension may be considered in future recommendations on the treatment of tricuspid regurgitation.

RIGHT VENTRICULAR DYSFUNCTION IN SEPSIS: AN UPDATED NARRATIVE REVIEW

ABSTRACT

Sepsis is a multisystem disease process, which constitutes a significant public health challenge and is associated with high morbidity and mortality. Among other systems, sepsis is known to affect the cardiovascular system, which may manifest as myocardial injury, arrhythmias, refractory shock, and/or septic cardiomyopathy. Septic cardiomyopathy is defined as the reversible systolic and/or diastolic dysfunction of one or both ventricles. Left ventricle dysfunction has been extensively studied in the past, and its prognostic role in patients with sepsis is well documented. However, there is relatively scarce literature on right ventricle (RV) dysfunction and its role. Given the importance of timely detection of septic cardiomyopathy and its bearing on prognosis of patients, the role of RV dysfunction has come into renewed focus. Hence, through this review, we sought to describe the pathophysiology of RV dysfunction in sepsis and what have we learnt so far about its multifactorial nature. We also elucidate the roles of different biomarkers for its detection and prognosis, along with appropriate management of such patient population.

Effect of pulmonary regurgitation on cardiac functions based on a human bi-ventricle model

BACKGROUND AND OBJECTIVE

Assessing the severity of pulmonary regurgitation (PR) and identifying optimal clinically relevant indicators for its treatment is crucial, yet standards for quantifying PR remain unclear in clinical practice. Computational modelling of the heart is in the process of providing valuable insights and information for cardiovascular physiology research. However, the advancements of finite element computational models have not been widely applied to simulate cardiac outputs in patients with PR. Furthermore, a computational model that incorporates both the left ventricle (LV) and right ventricle (RV) can be valuable in assessing the relationship between left and right ventricular morphometry and septal motion in PR patients. To enhance our understanding of the effect of PR on cardiac functions and mechanical behaviour, we developed a human bi-ventricle model to simulate five cases with varying degrees of PR severity.

METHODS

This bi-ventricle model was built using a patient-specific geometry and a widely used myofibre architecture. The myocardial material properties were described by a hyperelastic passive constitutive law and a modified time-varying elastance active tension model. To simulate realistic cardiac functions and the dysfunction of the pulmonary valve in PR disease cases, open-loop lumped parameter models representing systemic and pulmonary circulatory systems were designed.

RESULTS

In the baseline case, pressures in the aorta and main pulmonary artery and ejection fractions of both the LV and RV were within normal physiological ranges reported in the literature. The end-diastolic volume (EDV) of the RV under varying degrees of PR was comparable to the reported cardiac magnetic resonance imaging data. Moreover, RV dilation and interventricular septum motion from the baseline to the PR cases were clearly observed through the long-axis and short-axis views of the bi-ventricle geometry. The RV EDV in the severe PR case increased by 50.3% compared to the baseline case, while the LV EDV decreased by 18.1%. The motion of the interventricular septum was consistent with the literature. Furthermore, ejection fractions of both the LV and RV decreased as PR became severe, with LV ejection fraction decreasing from 60.5% at baseline to 56.3% in the severe case and RV ejection fraction decreasing from 51.8% to 46.8%. Additionally, the average myofibre stress of the RV wall at end-diastole significantly increased due to PR, from 2.7±12.1 kPa at baseline to 10.9±26.5 kPa in the severe case. The average myofibre stress of the LV wall at end-diastole increased from 3.7±18.1 kPa to 4.3±20.3 kPa.

CONCLUSIONS

This study established a foundation for the computational modelling of PR. The simulated results showed that severe PR leads to reduced cardiac outputs in both the LV and RV, clearly observable septum motion, and a significant increase in the average myofibre stress in the RV wall. These findings demonstrate the potential of the model for further exploration of PR.

The right ventricular dysfunction and ventricular interdependence in patients with DM: assessment using cardiac MR feature tracking

BACKGROUND

To investigate the difference of right ventricular (RV) structural and functional alteration in patients with diabetes mellitus (DM) with preserved left ventricular ejection fraction (LVEF), and the ventricular interdependence in these patients, using cardiac MR (CMR) feature tracking.

METHODS

From December 2016 to February 2022, 148 clinically diagnosed patients with DM who underwent cardiac MR (CMR) in our hospital were consecutively recruited. Fifty-four healthy individuals were included as normal controls. Biventricular strains, including left/right ventricular global longitudinal strain (LV-/RVGLS), left/right ventricular global circumferential strain (LV-/RVGCS), left/right ventricular global radial strain (LV-/RVGRS) were evaluated, and compared between patients with DM and healthy controls. Multiple linear regression and mediation analyses were used to evaluate DM's direct and indirect effects on RV strains.

RESULTS

No differences were found in age (56.98 ± 10.98 vs. 57.37 ± 8.41, p = 0.985), sex (53.4% vs. 48.1%, p = 0.715), and body surface area (BSA) (1.70 ± 0.21 vs. 1.69 ± 0.17, p = 0.472) between DM and normal controls. Patients with DM had decreased RVGLS (- 21.86 ± 4.14 vs. - 24.49 ± 4.47, p = 0.001), RVGCS (- 13.16 ± 3.86 vs. - 14.92 ± 3.08, p = 0.011), and no decrease was found in RVGRS (22.62 ± 8.11 vs. 23.15 ± 9.05, p = 0.743) in patients with DM compared with normal controls. The difference in RVGLS between normal controls and patients with DM was totally mediated by LVGLS (indirect effecting: 0.655, bootstrapped 95%CI 0.138-0.265). The difference in RVGCS between normal controls and DM was partly mediated by the LVGLS (indirect effecting: 0.336, bootstrapped 95%CI 0.002-0.820) and LVGCS (indirect effecting: 0.368, bootstrapped 95%CI 0.028-0.855).

CONCLUSIONS

In the patients with DM and preserved LVEF, the difference in RVGLS between DM and normal controls was totally mediated by LVGLS. Although there were partly mediating effects of LVGLS and LVGCS, the decrease in RVGCS might be directly affected by the DM.