The role of right ventricular function in paediatric idiopathic dilated cardiomyopathy

Echocardiographic Assessment of Right Ventricular Function in Paediatric Heart Disease: A Practical Clinical Approach

As the right ventricle (RV) plays an integral role in different paediatric heart diseases, the accurate assessment of RV size and function is essential in the diagnosis, management, and prognostication of congenital and acquired cardiac lesions. Yet, echocardiographic evaluation of the RV is challenging because of its complex and variable morphology, its different physiology compared with the left ventricle, and its capability to adapt to different loading conditions associated with congenital and acquired heart diseases within certain ranges. Reliable echocardiographic detection of RV systolic and diastolic dysfunction remains challenging while important for patient management. This review provides an updated, practical approach to assessing RV function in structurally normal hearts and in children with common congenital heart defects and in those with pulmonary hypertension. We also review the impact of tricuspid valve function on RV functional parameters. There is no single functional RV parameter that uniquely describes RV function; instead a combination of different parameters is recommended in clinical practice. Qualitative and quantitative analysis of RV function will be reviewed including more recent techniques such as speckle tracking and 3D echocardiography.

Longitudinal Prediction of Transplant-Free Survival by Echocardiography in Pediatric Dilated Cardiomyopathy

BACKGROUND

The prognostic significance of serial echocardiography and its rate of change in children with dilated cardiomyopathy (DCM) is incompletely defined.

METHODS

We retrospectively analysed up to 4 serial echocardiograms. Associations between mortality/transplant and echocardiographic parameters over time and between outcomes and the rate of change of echocardiographic parameters were analysed. Estimation of patient-specific intercepts and slopes was done using linear regression models.

RESULTS

Fifty-seven DCM children were studied (50% male; median age, 0.6 year; average follow-up, 2.1 ± 2.4 years). The median time to transplant or death was 2.0 years. Increased left ventricular (LV) diastolic (LVEDD) and systolic (LVESD) dimensions and myocardial performance index (MPI) were associated with increased mortality and transplant risk. Increased LV ejection fraction, mitral E-deceleration time, right ventricular (RV) fractional area change, and tricuspid annular plane systolic excursion were associated with reduced mortality and transplant risk. Transplant/mortality likelihood increased by 41.6% and 19.8% for each unit increase in LVEDD and LVESD z scores, respectively (LVEDD: hazard ratio [HR], 1.416; 95% confidence interval [CI], 1.285-1.560; P < 0.001; LVESD: HR, 1.198; 95% CI, 1.147-1.251; P < 0.001). A higher monthly change in LVESD z score increased transplant/mortality likelihood by 85.6% (HR, 1.856; 95% CI, 1.572-2.191; P = 0.015). Greater changes in mitral E/e' (HR, 0.707; 95% CI, 0.636-0.786; P < 0.001) and RV MPI (HR, 0.412; 95% CI, 0.277-0.613; P < 0.001) were associated with reduced mortality and transplant risk.

CONCLUSIONS

LV and RV systolic and diastolic dimensions and function over time and their rate of change are associated with risk for transplant and mortality in childhood DCM. Serial changes in these parameters may be useful to predict clinical outcomes.

Forgotten Right Ventricle in Pediatric Dilated Cardiomyopathy

To evaluate the right ventricular (RV) function in relation to that of the left ventricle (LV) in patients with dilated cardiomyopathy (DCM). Echocardiographic examination was done using tissue Doppler imaging (TDI) and two-dimensional speckle tracking echocardiography (2D-STE) for 32 pediatric patients with DCM comparing them to another 32 normal matched controls. The global longitudinal strain (GLS) derived from 2D-STE was used to reflect the LV systolic function. Tricuspid annular plan systolic excursion (TAPSE) and the following RV TDI derived indexes: peak systolic velocity (S'), peak early diastolic velocity E', peak late diastolic velocity A', isovolumic acceleration (IVA) and myocardial performance index (MPI) were measured. RV had significant systolic and diastolic dysfunction; TAPSE, S' velocity, IVA, peak early diastolic velocity (E') and peak early diastolic velocity/peak late diastolic velocity (E'/A') ratio were significantly decreased while MPI was significantly prolonged compared to controls. Moreover, TAPSE, S', IVA, E', E'/A' and RV MPI were significantly correlated to LV GLS. For prediction of LV dysfunction among patients, the area under the receiver operating characteristic curve was 0.98 for RV MPI, 0.906 for RV IVA. For identifying severe LV dysfunction; RV MPI  > 0.29 had 100% sensitivity and 93.7% specificity, while the RV IVA  ≤ 3 had 84.4% sensitivity and 90.6% specificity. In pediatric patients with DCM the RV systolic and diastolic functions are affected beside the LV dysfunction. Non-conventional echocardiographic evaluation of RV function is recommended in among this cohort.

Right Ventricular Dysfunction as an Echocardiographic Measure of Acute Rejection Following Heart Transplantation in Children

Noninvasive biomarkers of acute allograft rejection (AAR) following orthotopic heart transplantation (OHT) are needed. The aim of this study was to investigate the accuracy of echocardiographic (ECHO) right ventricular (RV) global functional and resistance indices in the detection of AAR. This retrospective chart review included children with biopsy-proven AAR (grade ≥ 2R cellular or CD4 + antibody-mediated rejection) following OHT and an ECHO within 12 h of the biopsy. ECHO measures: (a) ratio of systolic to diastolic duration (S/D), (b) RV myocardial performance index (MPI) and (c) tricuspid regurgitant gradient to RV outflow tract velocity time integral ratio (TRG/VTI), were derived at baseline, during AAR and at two follow-ups. Sixteen patients [56% male, mean (SD) age at OHT 3.5 (4.3) years] had 16 AAR episodes. S/D (1.15 vs. 1.60, p < 0.01), RV MPI (0.19 vs. 0.39, p < 0.01) and TRG/VTI (1.05 vs. 1.7, p = 0.01) deteriorated during AAR and, except for diastolic duration, improved significantly at first follow-up. The negative predictive values for S/D, RV MPI and TRG/VTI at cutoffs of 1.3, 0.31 and 1.3 were 97, 97 and 87%, respectively. RV S/D, MPI and TRG/VTI deteriorated during AAR. Their excellent negative predictive values suggest that their incorporation in surveillance may obviate the need for routine biopsies.

Early Biventricular Assist Device Use in Children: A Single-Center Review of 31 Patients

Biventricular assist device (BiVAD) support is considered a risk factor for worse outcomes compared with left ventricular assist device (LVAD) alone for children with end-stage heart failure. It remains unclear whether this is because of the morbidity associated with a second device or the underlying disease severity. We aimed to show that early BiVAD support can result in good survival by analyzing our prospectively collected database for all pediatric patients who underwent BiVAD implantation. From 2005 to 2009, BiVADs were used exclusively. From 2010 to 2014, LVAD alone was considered, maintaining a low threshold for BiVAD support. All BiVADs were pulsatile devices. Thirty-one patients with median age of 3.5 years received BiVAD support. Diagnoses included dilated cardiomyopathy in 17 (55%), myocarditis in 6 (19%), and congenital heart disease in 3 (10%). Survival to transplant was achieved in 27 (87%) with a median duration of 41 days (interquartile range, 15-69). Adverse event rates (per 100 days of support) were bleeding at 0.52, infection at 1.17, and central nervous system dysfunction at 0.78. Of those who survived to transplant, 26 (96%) remain alive with a median follow-up of 55 months. These results show that BiVAD support can bridge patients to transplant with excellent long-term survival.

Ventricular assist device use in congenital heart disease with a comparison to heart transplant

Despite advances in medical and surgical therapies, some children with congenital heart disease (CHD) are not able to be adequately treated or palliated, leading them to develop progressive heart failure. As these patients progress to end-stage heart failure they pose a unique set of challenges. Heart transplant remains the standard of care; the donor pool, however, remains limited. Following the experience from the adult realm, the pediatric ventricular assist device (VAD) has emerged as a valid treatment option as a bridge to transplant. Due to the infrequent necessity and the uniqueness of each case, the pediatric VAD in the CHD population remains a topic with limited information. Given the experience in the adult realm, we were tasked with reviewing pediatric VADs and their use in patients with CHD and comparing this therapy to heart transplantation when possible.

Current approaches to device implantation in pediatric and congenital heart disease patients

The pediatric ventricular assist device (VAD) has recently shown substantial improvements in survival as a bridge to heart transplant for patients with end-stage heart failure. Since that time, its use has become much more frequent. With increasing utilization, additional questions have arisen including patient selection, timing of VAD implantation and device selection. These challenges are amplified by the uniqueness of each patient, the recent abundance of literature surrounding VAD use as well as the technological advancements in the devices themselves. Ideal strategies for device placement must be sought, for not only improved patient care, but also for optimal resource utilization. Here, we review the most relevant literature to highlight some of the challenges facing the heart failure specialist, and any physician, who will care for a child with a VAD.