Mid-term outcomes of right ventricular papillary muscle approximation for severe functional tricuspid regurgitation.

OBJECTIVES: Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering follows. We previously reported a new technique of the right ventricular papillary muscle approximation (RV-PMA) for functional TR associated with leaflet tethering. The objective of this study is to elucidate the mid-term outcomes and evaluate the durability of RV-PMA. METHODS: Between January 2014 and March 2023, we applied RV-PMA in 20 patients of advanced functional TR with severe leaflet tethering. The indication of the technique was severe TR with leaflet tethering height >8 mm, and/or a right ventricular end-diastolic diameter >45 mm. The patients were followed up with echocardiography before discharge and at annual interval thereafter. RESULTS: There was no perioperative mortality. In the echocardiography performed before discharge, TR was decreased to mild or less in 85%, and a significant improvement in right ventricular end-diastolic diameter and tethering height were achieved (53-45 mm and 11.1-4.4 mm, respectively). Furthermore, during the median 3-year follow-up period, TR was kept controlled mild or less in 80% of the cases. CONCLUSIONS: RV-PMA is considered to be a safe, effective and durable technique as an additional approach for tricuspid annuloplasty.

Comparative analysis of ventricular stiffness across species.

Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms of cardiovascular disorders. Ventricular stiffness, a fundamental parameter that defines ventricular diastolic functions in chordates, is typically analyzed using the end-diastolic pressure-volume relationship (EDPVR). However, comparing ventricular stiffness accurately across chambers of varying maximum volume capacities has been a long-standing challenge. As one of the solutions to this problem, we propose calculating a relative ventricular stiffness index by applying an exponential approximation formula to the EDPVR plot data of the relationship between ventricular pressure and values of normalized ventricular volume by the ventricular weight. This article reviews the potential, utility, and limitations of using normalized EDPVR analysis in recent studies. Herein, we measured and ranked ventricular stiffness in differently sized and shaped chambers using ex vivo ventricular pressure-volume analysis data from four animals: Wistar rats, red-eared slider turtles, masu salmon, and cherry salmon. Furthermore, we have discussed the mechanical effects of intracellular and extracellular viscoelastic components, Titin (Connectin) filaments, collagens, physiological sarcomere length, and other factors that govern ventricular stiffness. Our review provides insights into the comparison of ventricular stiffness in different-sized ventricles between heterologous and homologous species, including non-model organisms.

Intrinsic mechanisms of right ventricular autoregulation.

To elucidate the adaptation of the right ventricle to acute and intermittently sustained afterload elevation, targeted preload reductions and afterload increases were implemented in a porcine model involving 12 pigs. Preload reduction was achieved via balloon occlusion of the inferior vena cava before, immediately and 5 min after acute afterload elevation induced by pulmonary artery occlusion or thromboxane A2 analog (U46619) infusion. Ventricular response was monitored by registration of pressure-volume (PV) loops using a conductance catheter. The end-systolic pressure-volume relationship (ESPVR) during pure preload reduction was adequately described by linear regression (mean and SEM slope of ESPVR (Ees) 0.414 ± 0.064 mmHg/ml), reflecting the classical Frank-Starling mechanism (FSM). The ESPVR during acute afterload elevation exhibited a biphasic trajectory with significantly distinct slopes (mean and SEM Ees bilin1: 1.256 ± 0.066 mmHg ml; Ees bilin2: 0.733 ± 0.063 mmHg ml, p < 0.001). The higher slope during the first phase in the absence of ventricular dilation could be explained by a reduced amount of shortening deactivation (SDA). The changes in PV-loops during the second phase were similar to those observed with a preload intervention. The persistent increase in afterload resulted in an increase in the slopes of ESPVR and preload recruitable stroke work (PRSW) with a slight decrease in filling state, indicating a relevant Anrep effect. This effect became more pronounced after 5 min or TXA infusion. This study demonstrates, for the first time, the relevance of intrinsic mechanisms of cardiac autoregulation in the right ventricle during the adaptation to load. The SDA, FSM, and Anrep effect could be differentiated and occurred successively, potentially with some overlap. Notably, the Anrep effect serves to prevent ventricular dilation.

Durable ventricular assist device in adult patients with single ventricle: a systematic literature review.

The worldwide experience with mechanical circulatory support in adult patients with single ventricle and Fontan palliation is limited. We aimed to see the outcomes in such patients on durable left ventricular assist device. We systematically reviewed the English language literature found on PubMed and Google Scholar, searching the terms "Fontan," "single ventricle," "ventricular assist device," "LVAD," and "mechanical circulatory support," and selected all individual cases with reported outcomes. We identified 4 patients on pulsatile left ventricular assist device, all of whom were successfully bridged to transplant, and 15 patients on continuous flow LVAD, age 25.9 ± 5.8, predominantly males. Mean time on LVAD support was 718.6 ± 616.5 days, and only 2 patients (13.3%) died. Durable left ventricular assist device support in adult patients with Fontan provides excellent results and should be used more frequently.

Decreased erythrocyte aggregation in Glenn and Fontan: univentricular circulation as a rheologic disease model.

BACKGROUND: In the Fontan palliation for single ventricle heart disease (SVHD), pulmonary blood flow is non-pulsatile/passive, low velocity, and low shear, making viscous power loss a critical determinant of cardiac output. The rheologic properties of blood in SVHD patients are essential for understanding and modulating their limited cardiac output and they have not been systematically studied. We hypothesize that viscosity is decreased in single ventricle circulation. METHODS: We evaluated whole blood viscosity, red blood cell (RBC) aggregation, and RBC deformability to evaluate changes in healthy children and SVHD patients. We altered suspending media to understand cellular and plasma differences contributing to rheologic differences. RESULTS: Whole blood viscosity was similar between SVHD and healthy at their native hematocrits, while viscosity was lower at equivalent hematocrits for SVHD patients. RBC deformability is increased, and RBC aggregation is decreased in SVHD patients. Suspending SVHD RBCs in healthy plasma resulted in increased RBC aggregation and suspending healthy RBCs in SVHD plasma resulted in lower RBC aggregation. CONCLUSIONS: Hematocrit corrected blood viscosity is lower in SVHD vs. healthy due to decreased RBC aggregation and higher RBC deformability, a viscous adaptation of blood in patients whose cardiac output is dependent on minimizing viscous power loss. IMPACT: Patients with single ventricle circulation have decreased red blood cell aggregation and increased red blood cell deformability, both of which result in a decrease in blood viscosity across a large shear rate range. Since the unique Fontan circulation has very low-shear and low velocity flow in the pulmonary arteries, blood viscosity plays an increased role in vascular resistance, therefore this work is the first to describe a novel mechanism to target pulmonary vascular resistance as a modifiable risk factor. This is a novel, modifiable risk factor in this patient population.

Right ventricular-pulmonary artery coupling is an independent risk factor for coronary artery lesions in children with Kawasaki disease.

BACKGROUND: The recognition ability of right ventricular-pulmonary artery (RV-PA) coupling for coronary artery lesions (CAL) in children with Kawasaki disease (KD) has not been well characterized. This study aimed to determine whether RV-PA coupling is an independent the risk factors for CAL in children with KD. METHODS: Between October 2021 and August 2023, RV-PA coupling was assessed in 59 KD children using the ratio between echocardiographic tricuspid annular plane systolic excursion and pulmonary artery systolic pressure (PASP). Multivariable logistic regression analysis was used to identify the independent risk factors for CAL among the demographic, clinical, laboratory and echocardiographic data. RESULTS: Twenty-nine of 59 KD children had CAL according to the diagnostic criteria of echocardiography. There were significantly different white blood cell count, C-reactive protein, erythrocyte sedimentation rate, left ventricular ejection fraction, PASP and RV-PA coupling at admission, and significantly different acute/subacute phase ratio of RV-PA coupling between KD children with and without CAL ( P  < 0.05). Multivariate logistic regression analysis identified that acute/subacute phase ratio of RV-PA coupling (OR = 26.800; 95% CI, 1.276-562.668; P  = 0.034) was an independent risk factor for CAL in children with KD. The area under receiver operating characteristic curve for the acute/subacute phase ratio of RV-PA coupling was 0.715 (95%CI: 0.624 - 0.825) to predict CAL in KD children ( P  < 0.05), with a sensitivity of 81.25% and a specificity of 62.57% at the optimal cutoff value of 0.839. CONCLUSION: The acute/subacute phase ratio of RV-PA coupling was an independent risk factor for CAL in KD children.

Ventricular Electrocardiographic Signatures Associated with Dementia and Plasma Alzheimer's Disease Biomarkers in Older Adults: A Population-Based Study.

BACKGROUND: Evidence has emerged that altered ventricular electrocardiogram profiles are associated with dementia, but the neuropathological mechanisms underlying their associations are poorly understood. OBJECTIVE: To investigate the interrelationships of ventricular electrocardiogram profiles with dementia and plasma Alzheimer's disease (AD) biomarkers among older adults. METHODS: This population-based cross-sectional study included 5,153 participants (age ≥65 years; 57.3% women) living in rural communities in China; of these, 1,281 had data on plasma amyloid-ß (Aß)40, Aß42, total-tau, and neurofilament light chain (NfL) protein. The QT, QTc, JT, JTc, QRS intervals, and QRS axis were derived from the 10-second electrocardiogram recording. The DSM-IV criteria were followed for clinical diagnosis of dementia, the NIA-AA criteria for AD, and the NINDS-AIREN criteria for vascular dementia (VaD). Data were analyzed using general linear models, multinomial logistic models, and restricted cubic splines. RESULTS: Of the 5,153 participants, 299 (5.8%) were diagnosed with dementia, including 194 with AD and 94 with VaD. Prolonged QT, QTc, JT, and JTc intervals were significantly associated with all-cause dementia, AD, and VaD (p < 0.05). Left QRS axis deviation was significantly associated with all-cause dementia and VaD (p < 0.01). In the subsample of plasma biomarkers (n = 1,281), prolonged QT, JT, and JTc intervals were significantly associated with a lower Aß42/Aß40 ratio and higher plasma NfL concentrations (p < 0.05). CONCLUSION: Alterations in ventricular repolarization and depolarization are independently associated with all-cause dementia, AD, VaD, and AD plasma biomarkers in older adults (age ≥65 years). Ventricular electrocardiogram parameters may be valuable clinical markers for dementia and the underlying AD pathologies and neurodegeneration.

How to incorporate tricuspid regurgitation in right ventricular-pulmonary arterial coupling.

Adaptation of the right ventricle (RV) to a progressively increasing afterload is one of the hallmarks of pulmonary arterial hypertension (PAH). Pressure-volume loop analysis provides measures of load-independent RV contractility, i.e., end-systolic elastance, and pulmonary vascular properties, i.e., effective arterial elastance (Ea). However, PAH-induced RV overload potentially results in tricuspid regurgitation (TR). TR makes RV eject to both PA and right atrium; thereby, a ratio of RV end-systolic pressure (Pes) to RV stroke volume (SV) could not correctly define Ea. To overcome this limitation, we introduced a two-parallel compliance model, i.e., Ea = 1/(1/Epa + 1/ETR), while effective pulmonary arterial elastance (Epa = Pes/PASV) represents pulmonary vascular properties and effective tricuspid regurgitant elastance (ETR) represents TR. We conducted animal experiments to validate this framework. First, we performed SV analysis with a pressure-volume catheter in the RV and a flow probe at the aorta in rats with and without pressure-overloaded RV to determine the effect of inferior vena cava (IVC) occlusion on TR. A discordance between the two techniques was found in rats with pressure-overloaded RV, not in sham. This discordance diminished after IVC occlusion, suggesting that TR in pressure-overloaded RV was diminished by IVC occlusion. Next, we performed pressure-volume loop analysis in rats with pressure-overloaded RVs, calibrating RV volume by cardiac magnetic resonance. We found that IVC occlusion increased Ea, suggesting that a reduction of TR increased Ea. Using the proposed framework, Epa was indistinguishable to Ea post-IVC occlusion. We conclude that the proposed framework helps better understanding of the pathophysiology of PAH and associated right heart failure.NEW & NOTEWORTHY This study reveals the impact of tricuspid regurgitation on pressure-volume loop analysis in right ventricle pressure overload. By introducing a novel concept of parallel compliances in the pressure-volume loop analysis, a better description is provided for the right ventricular forward afterload in the presence of tricuspid regurgitation.

Evaluación multiparamétrica de la función ventricular derecha en la hipertensión arterial pulmonar asociada a cardiopatías congénitas / Multiparametric evaluation of right ventricular function in pulmonary arterial hypertension associated with congenital heart disease

Introducción y objetivos El pronóstico de los pacientes con cardiopatía congénita e hipertensión arterial pulmonar (HTP) está estrechamente relacionado con la función del ventrículo derecho (VD). Los parámetros de ecocardiografía bidimensional como la deformación miocárdica o el índice de remodelado VD telesistólico (IRVDTS) han surgido para cuantificar la función del VD. Métodos Se estudió de forma prospectiva a 30 paciente de edad 48± 12 años con shunt pretricuspídeo e HTP para investigar la precisión de diversos parámetros ecocardiográficos de estudio de la función del VD (extrusión sistólica del anillo tricúspide, velocidad sistólica pico del anillo tricúspide, ratio de duración sistodiastólica del VD, área de la aurícula derecha, cambio de área fraccional del ventrículo derecho, deformación miocárdica global del ventrículo derecho e IRVDTS) respecto a la fracción de eyección del ventrículo derecho medida por resonancia cardiaca. Resultados En 13 pacientes (43,3%) se observó una fracción de eyección del VD <45%. La deformación longitudinal global del VD (ρ [coeficiente de correlación de Spearman] = −0,75, p=0,001; R2=0,58, p=0,001), área de la aurícula derecha (ρ=−0,74, p <0,0001; R2=0,56, p <0,0001); IRVDTS (ρ=−0,64, p < 0,0001; R2=0,47, p <0,0001), ratio de duración sistodiastólica (ρ=−0,62, p=0,0004; R2=0,47, p <0,0001) y cambio de área fraccional del VD (ρ=0,48, p=0,01; R2=0,37, p <0,0001) se correlacionaron con la fracción de eyección del VD. La deformación longitudinal global del VD, IRVDTS y área de la aurícula derecha fueron predictores de fracción de eyección <45% con la mayor área bajo la curva (0,88; IC95%, 0,71-1,00; 0,88; IC95%, 0,76-1,00 y 0,89; IC95%, 0,77-1,00, respectivamente). Una deformación longitudinal global del VD> −16%, IRVDTS ≥ 1,7 y un área de la aurícula derecha ≥ 22 cm2 predijeron una fracción de eyección del VD <45% con una sensibilidad y especificidad del 87,5 y 85,7%; 76,9 y 88,3%; 92,3 y 82,4%, respectivamente (AU)

Introduction and objectives Outcome in patients with congenital heart diseases and pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Two-dimensional echocardiographic parameters, such as strain imaging or RV end-systolic remodeling index (RVESRI) have emerged to quantify RV function. Methods We prospectively studied 30 patients aged 48±12 years with pretricuspid shunt and PAH and investigated the accuracy of multiple echocardiographic parameters of RV function (tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity, RV systolic-to-diastolic duration ratio, right atrial area, RV fractional area change, RV global longitudinal strain and RVESRI) to RV ejection fraction measured by cardiac magnetic resonance. Results RV ejection fraction <45% was observed in 13 patients (43.3%). RV global longitudinal strain (ρ [Spearman's correlation coefficient]=−0.75; P=.001; R2=0.58; P=.001), right atrium area (ρ=−0.74; P <.0001; R2=0.56; P <.0001), RVESRI (ρ=−0.64; P <.0001; R2=0.47; P <.0001), systolic-to-diastolic duration ratio (ρ=−0.62; P=.0004; R2=0.47; P <.0001) and RV fractional area change (ρ=0.48; P=.01; R2=0.37; P <.0001) were correlated with RV ejection fraction. RV global longitudinal strain, RVESRI and right atrium area predicted RV ejection fraction <45% with the greatest area under curve (0.88; 95%CI, 0.71-1.00; 0.88; 95%CI, 0.76-1.00, and 0.89; 95%CI, 0.77-1.00, respectively). RV global longitudinal strain >−16%, RVESRI ≥ 1.7 and right atrial area ≥ 22 cm2 predicted RV ejection fraction <45% with a sensitivity and specificity of 87.5% and 85.7%; 76.9% and 88.3%; 92.3% and 82.4%, respectively. Conclusions RVESRI, right atrial area and RV global longitudinal strain are strong markers of RV dysfunction in patients with pretricuspid shunt and PAH (AU)