Regional right ventricular remodeling and function in children with idiopathic pulmonary arterial hypertension vs those with pulmonary valve stenosis: Insights into mechanics of right ventricular dysfunction.

Right ventricular (RV) pressure overload in the context of pulmonary stenosis (PS) has a much better prognosis than in the context of idiopathic pulmonary arterial hypertension (iPAH), which may be related to differences in global and regional RV remodeling and systolic function. We compared RV mechanics in children with PS to those with iPAH, aiming to identify mechanisms and markers of RV dysfunction. Eighteen controls, 18 iPAH and 16 PS patients were retrospectively studied. Age, BSA, and sex distribution were comparable. Two-dimensional echocardiography, blood flow and tissue Doppler, and longitudinal RV deformation were analyzed. ANCOVA-including RV systolic pressure (RVSP) and length as covariates-was used to compare patient groups. RV systolic pressure was higher in iPAH vs PS (96.8±25.4 vs 75.4±18.9 mm Hg, P=.011). Compared to controls, PS patients showed mild dilation (P<.01) and decreased longitudinal deformation (P<.001) at the RV apex. Compared to both PS and controls, iPAH patients showed marked spherical RV dilation (P<.001), reduced global, RV free wall and septal longitudinal deformation (iPAH -22.07%±4.35% vs controls -28.18%±1.69%; -9.98%±4.30% vs -17.45%±2.52%; P<.001) and RV postsystolic shortening (P<.001). RV transverse shortening (radial performance) was increased in PS (31.75%±10.35%; P<.001) but reduced in iPAH (-1.62%±11.11% vs controls 12.00%±7.74%; P<.001). Children with iPAH demonstrate adverse global and regional RV remodeling and mechanics compared to those with PS. Mechanisms of RV systolic dysfunction in iPAH include decreased longitudinal deformation, decreased or absent transverse shortening, and postsystolic shortening. These markers may be useful to identify children at risk of RV failure.

Driessen MMP ，Meijboom FJ ，Hui W ，Dragulescu A ，Mertens L ，Friedberg MK ... -  《-》

Adverse ventricular-ventricular interactions in right ventricular pressure load: Insights from pediatric pulmonary hypertension versus pulmonary stenosis.

Right ventricular (RV) pressure overload has a vastly different clinical course in children with idiopathic pulmonary arterial hypertension (iPAH) than in children with pulmonary stenosis (PS). While RV function is well recognized as a key prognostic factor in iPAH, adverse ventricular-ventricular interactions and LV dysfunction are less well characterized and the pathophysiology is incompletely understood. We compared ventricular-ventricular interactions as hypothesized drivers of biventricular dysfunction in pediatric iPAH versus PS Eighteen iPAH, 16 PS patients and 18 age- and size-matched controls were retrospectively studied. Cardiac cycle events were measured by M-mode and Doppler echocardiography. Measurements were compared between groups using ANOVA with post hoc Dunnet's or ANCOVA including RV systolic pressure (RVSP; iPAH 96.8 ± 25.4 mmHg vs. PS 75.4 ± 18.9 mmHg; P = 0.011) as a covariate. RV-free wall thickening was prolonged in iPAH versus PS, extending beyond pulmonary valve closure (638 ± 76 msec vs. 562 ± 76 msec vs. 473 ± 59 msec controls). LV and RV isovolumetric relaxation were prolonged in iPAH (P < 0.001; LV 102.8 ± 24.1 msec vs. 63.1 ± 13.7 msec; RV 95 [61-165] vs. 28 [0-43]), associated with adverse septal kinetics; characterized by rightward displacement in early systole and leftward displacement in late RV systole (i.e., early LV diastole). Early LV diastolic filling was decreased in iPAH (73 ± 15.9 vs. PS 87.4 ± 14.4 vs. controls 95.8 ± 12.5 cm/sec; P = 0.004). Prolonged RVFW thickening, prolonged RVFW isovolumetric times, and profound septal dyskinesia are associated with interventricular mechanical discoordination and decreased early LV filling in pediatric iPAH much more than PS These adverse mechanics affect systolic and diastolic biventricular efficiency in iPAH and may form the basis for worse clinical outcomes. We used clinically derived data to study the pathophysiology of ventricular-ventricular interactions in right ventricular pressure overload, demonstrating distinct differences between pediatric pulmonary arterial hypertension (iPAH) and pulmonary stenosis (PS). Altered timing of right ventricular free wall contraction and profound septal dyskinesia are associated with interventricular mechanical discoordination and decreased early LV filling in iPAH much more than PS These adverse mechanics affect systolic and diastolic biventricular efficiency, independent of right ventricular systolic pressure.

Driessen MM ，Hui W ，Bijnens BH ，Dragulescu A ，Mertens L ，Meijboom FJ ，Friedberg MK ... -  《Physiological Reports》

Longitudinal assessment of right ventricular myocardial strain in relation to transplant-free survival in children with idiopathic pulmonary hypertension.

Right ventricular (RV) function is an important determinant of mortality in patients with idiopathic pulmonary arterial hypertension (iPAH). The aim of this study was to serially evaluate global and regional RV two-dimensional strain and their relation to transplantation-free survival in children with iPAH. RV regional and global longitudinal strain was retrospectively assessed in children with iPAH. Serial echocardiograms at 3 to 6 months from presentation and then at yearly intervals were analyzed. Results were compared with those from controls and between iPAH survivors (group 1) and those who died or needed transplantation (group 2). Survival stratified by RV global longitudinal strain at presentation was analyzed. Seventeen patients with iPAH (mean age, 8.4 ± 4.8 years; seven male patients), of whom 11 were alive (group 1) and six had died or undergone transplantation (group 2), and 17 age-matched controls were studied. The median follow-up period was 1.5 years (range, 0.04-7.8 years). RV global longitudinal strain was significantly reduced in patients with iPAH compared with controls (-13.5 ± 5.9% vs -24.4 ± 3.9%, P < .001) and in group 2 compared with group 1 at presentation (-9 ± 2.8% vs -16 ± 5.7%, P < .05) and throughout follow-up. During follow-up, RV global and regional longitudinal strain worsened in group 2, especially in RV apical segments (-6.3 ± 5% vs -1.9 ± 1.6% at presentation compared with the last echocardiographic assessment in group 2, P < .05), but was unchanged in group 1. RV global longitudinal strain > -14% predicted transplantation-free survival with 100% sensitivity and 54.5% specificity. RV strain imaging may be useful for serial follow-up and prognostication in children with iPAH.

Okumura K ，Humpl T ，Dragulescu A ，Mertens L ，Friedberg MK ... -  《-》

RV adaptation to increased afterload in congenital heart disease and pulmonary hypertension.

Driessen MMP ，Leiner T ，Sieswerda GT ，van Dijk APJ ，Post MC ，Friedberg MK ，Mertens L ，Doevendans PA ，Snijder RJ ，Hulzebos EH ，Meijboom FJ ... -  《PLoS One》

Right ventricular remodeling in idiopathic pulmonary arterial hypertension: adaptive versus maladaptive morphology.

Although increased pulmonary pressure is caused by changes in the pulmonary vasculature, prognosis in idiopathic pulmonary arterial hypertension (IPAH) is strongly associated with right ventricular (RV) function. The aim of this study was to describe the best RV adaptive remodeling pattern to increased afterload in IPAH. In 60 consecutive patients with IPAH, RV morphologic and functional features were evaluated by echocardiography and cardiac magnetic resonance imaging. To address the question of the best RV adaptation pattern, we divided the study population into two groups by the median value of RV mass/volume ratio (0.46) because this parameter allows the distinction between RV eccentric (≤0.46) and concentric hypertrophy (>0.46). The two groups were compared for RV remodeling and systolic function parameters, World Health Organization class, pulmonary hemodynamics, and 6-minute walk test. Despite similar pulmonary vascular resistance, mean pulmonary pressure, and compliance, patients with eccentric hypertrophy had advanced World Health Organization class and worse 6-minute walk test, hemodynamics, RV remodeling, and systolic function parameters compared with patients with concentric hypertrophy. The group with concentric hypertrophy had higher RV to pulmonary arterial coupling compared with the group with eccentric hypertrophy (1.24 ± 0.26 vs 0.83 ± 0.33, p = 0.0001), indicating higher RV efficiency. A significant correlation was found between pulmonary vascular resistance and RV to pulmonary arterial coupling (r = -0.55, r(2) = 0.31, p = 0.0001), with patients with RV mass/volume ratio > 0.46 at the higher part of the scatterplot, confirming more adequate RV function. Concentric hypertrophy might represent a more favorable RV adaptive remodeling pattern to increased afterload in IPAH because it is associated with more suitable systolic function and mechanical efficiency.

Badagliacca R ，Poscia R ，Pezzuto B ，Nocioni M ，Mezzapesa M ，Francone M ，Giannetta E ，Papa S ，Gambardella C ，Sciomer S ，Volterrani M ，Fedele F ，Dario Vizza C ... -  《-》