39 research outputs found

    The adult heart requires baseline expression of the transcription factor Hand2 to withstand RV pressure overload

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    AIMS: Research on the pathophysiology of right ventricular (RV) failure has, in spite of the associated high mortality and morbidity, lagged behind compared to the left ventricle (LV).Previous work from our lab revealed that the embryonic basic helix-loop-helix transcription factor heart and neural crest derivatives expressed-2 (Hand2) is re-expressed in the adult heart and activates a 'fetal gene program' contributing to pathological cardiac remodeling under conditions of LV pressure overload. As such, ablation of cardiac expression of Hand2 conferred protection to cardiac stress and abrogated the maladaptive effects that were observed upon increased expression levels. In this study, we aimed to understand the contribution of Hand2 to RV remodeling in response to pressure overload induced by pulmonary artery banding (PAB). METHODS AND RESULTS: In the present study, Hand2F/F and MCM- Hand2F/F mice were treated with tamoxifen (control and knockout, respectively) and subjected to six weeks of RV pressure overload induced by PAB. Echocardiographic- and MRI-derived hemodynamic parameters as well as molecular remodeling were assessed for all experimental groups and compared to sham-operated controls. Six weeks after PAB, levels of Hand2 expression increased in the control banded animals but, as expected, remained absent in the knockout hearts. Despite the dramatic differences in Hand2 expression, pressure overload resulted in impaired cardiac function independently of the genotype. In fact, Hand2 depletion seems to sensitize the RV to pressure overload as these mice develop more hypertrophy and more severe cardiac dysfunction. Higher expression levels of HAND2 were also observed in RV samples of human hearts from patients with pulmonary hypertension. In turn, the LV of RV-pressure overloaded hearts was also dramatically affected as reflected by changes in shape, decreased LV mass and impaired cardiac function. RNA sequencing revealed a distinct set of genes that are dysregulated in the pressure-overloaded RV, compared to the previously described pressure-overloaded LV. CONCLUSIONS: Cardiac-specific depletion of Hand2 is associated with severe cardiac dysfunction in conditions of RV pressure overload. While inhibiting Hand2 expression can prevent cardiac dysfunction in conditions of LV pressure overload, the same does not hold true for conditions of RV pressure overload. This study highlights the need to better understand the molecular mechanisms driving pathological remodeling of the RV in contrast to the LV, in order to better diagnose and treat patients with RV or LV failure. TRANSLATIONAL PERSPECTIVE: RV failure associated with pulmonary hypertension reduces long-term survival rate to 55% within 3 years, suggesting that 3 years after diagnosis almost half of the patients will die. To revert these numbers an adequate RV-specific and, therefore, more efficient treatment is needed. Our work suggests that current therapies and potential mechanisms underlying LV failure may not be suitable for RV failure. While Hand2 deletion is favorable in LV response to stress, it is particularly detrimental in the RV under similar conditions, and thus, highlighting potential severe consequences of not differentiating therapeutic targets or treatment for RV or LV failure

    A Multicenter, Long-Term Study on Arrhythmias in Children with Ebstein Anomaly

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    To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff–Parkinson–White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA, diagnosed, and followed by pediatric cardiologists between 1980 and 2005 in The Netherlands. During a follow-up after EA diagnosis of 13 years 3 months (range: 6 days to 28 years 2 months), 16 (17%) of the 93 pediatric EA patients exhibited rhythm disturbances. Nine patients showed arrhythmic events starting as of the neonatal period. Supraventricular tachycardia was noted in 11 patients. One patient died in the neonatal period due to intractable supraventricular tachycardia resulting in heart failure and one patient died at 5 weeks of age most probably due to an arrhythmic event. The 14 surviving patients all show preexcitation, albeit 4 of them intermittently, and all have a right-sided accessory pathway location. Nine patients underwent catheter ablation of an accessory pathway. Only four patients are currently on antiarrhythmic drugs. The 17% prevalence of rhythm disturbances in pediatric EA patients, most commonly supraventricular arrhythmias, is significantly lower than in adult EA patients. Life-threatening rhythm disturbances are not frequent early in life. Symptomatic patients are well treated with radiofrequency catheter ablation

    Inspiratory muscle unloading by neurally adjusted ventilatory assist during maximal inspiratory efforts in healthy subjects.

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    none7noneSinderby C; Beck J; Spahija J; de Marchie M; Lacroix J; Navalesi P; Slutsky ASSinderby, C; Beck, J; Spahija, J; de Marchie, M; Lacroix, J; Navalesi, P; Slutsky, A

    Impact of introduction of 20-week ultrasound scan on prevalence and fetal and neonatal outcomes in cases of selected severe congenital heart defects in The Netherlands

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    OBJECTIVES: To evaluate in a population-based cohort the effect of the introduction of the 20-week ultrasound scan in 2007 on the time of diagnosis, pregnancy outcome and total prevalence and liveborn prevalence of cases with selected congenital heart defects (CHDs) in The Netherlands. METHODS: We included children and fetuses diagnosed with selected severe CHD, born in the 11-year period from 2001 to 2011. Two groups of CHD were defined: those associated with an abnormal four-chamber view at ultrasound (Group 1), and those associated with a normal four-chamber view at ultrasound (Group 2). The time of diagnosis, pregnancy outcome and total liveborn prevalence were compared for both groups over two 5-year periods, before and after the introduction of the 20-week ultrasound scan. Trends in total and liveborn prevalence were examined over 2001 to 2011. RESULTS: Information was collected on 269 children and fetuses. After the introduction of the 20-week ultrasound scan, the prenatal detection rate of CHDs increased in both groups (Group 1, 34.6% in 2001-2005 vs 84.8% in 2007-2011 (P < 0.001); Group 2, 14.3% in 2001-2005 vs 29.6% in 2007-2011 (P = 0.037)). The rate of termination of pregnancy (TOP) increased significantly only for Group 1 (15.4% vs 51.5% (P < 0.001)). The total prevalence of CHD in Group 1 increased over time from 2.9 per 10 000 births in 2001 to 6.4 per 10 000 births in 2011 (P = 0.016). The liveborn prevalence did not show a trend over time. For Group 2, no trends in total or liveborn prevalence could be detected over time. CONCLUSIONS: Since the implementation of the routine 20-week ultrasound scan in The Netherlands, prenatal detection rate of selected severe CHDs increased significantly. Improved prenatal detection was accompanied by a more than three-fold increase in TOP, although only in those CHDs with an abnormal four-chamber view at prenatal ultrasound

    Paediatric Ebstein's anomaly: How clinical presentation predicts mortality

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    Background Forecasting the prognosis of a child when diagnosed with Ebstein's anomaly is difficult. We, therefore, studied which factors at the time of diagnosis are associated with death during childhood. Methods All consecutive patients (0-18 years) diagnosed with Ebstein's anomaly in the Netherlands between 1980 and 2014 were included. Survival curves were obtained using the Kaplan-Meier method. By using the Cox proportional hazard model, we analysed the factors (at diagnosis) that were associated with death. Results We included 176 patients. Thirty-one patients (18%) died before the age of 18 years. The 1-year survival was 84% and remained stable at 82% from 35 months after diagnosis and onwards. Modified Ross Heart Failure Class 4 at the time of diagnosis was the most important risk factor for death during childhood (HR 12.5, 95% CI 4.4 to 35.9). Furthermore, diagnosis in the neonatal period (HR 4.2, 95% CI 1.5 to 12.0), severe tricuspid valve regurgitation (HR 2.4, 95% CI 1.2 to 5.0), severe right ventricular outflow tract obstruction (HR 3.7, 95% CI 1.8 to 7.7) and a patent ductus arteriosus (HR 2.8, 95% CI 1.3 to 6.0) at the time of diagnosis were univariately associated with death. Multivariable analysis showed that presentation with Heart Failure Class 4 and a ventricular septal defect is the strongest predictor of death in childhood and adolescence. Conclusion Patients with Ebstein's anomaly presenting with Heart Failure Class 4 and a ventricular septal defect have a high risk of death during childhood

    Growth patterns in fetuses with isolated cardiac defects

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    Objectives: There is evidence that in fetuses with congenital heart defects (CHDs), head growth is affected. However, scanty data are available on longitudinal growth patterns of other biometric parameters such as abdominal circumference (AC) and femur length (FL). The aim was to evaluate growth patterns in fetuses with isolated CHD diagnosed prenatally in different categories of lesions. Methods: Fetuses with isolated CHD seen between 2008 and 2013 at the Fetal Medicine Unit of 2 tertiary referral centers were retrospectively included in the study. CHD was classified into 7 categories. Fetal biometry parameters were assessed at 4 variable time points between 18 and 35 weeks' gestation and transformed into Z scores. Linear mixed modeling was performed to analyze repeated measurements and construction of growth models. Results: Two hundred forty-six live births with CHD were analyzed. Linear growth modeling showed a slight decrease in head circumference (HC) in the second half of pregnancy, whereas AC and FL growth were not significantly affected. The model predicted a significantly smaller HC at 36 weeks' gestation in fetuses with conotruncal heart defects. Conclusions: Fetuses with CHD showed a modest but significant linear decrease in HC growth, whereas AC and FL growth trajectories remained stable
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