Dilated Cardiomyopathy and Heart Failure in Children

Focused Cardiac Ultrasound Diagnosis of Dilated Cardiomyopathy

ABSTRACT

We report the case of a 6-year-old boy presenting to the emergency department after a syncopal event during a flu-like illness. Intermittent ventricular tachycardia was noted during Emergency Medical Services transport, and a focused cardiac ultrasound (FOCUS) in the emergency department revealed a dilated left ventricle and left atrium as well as severe global systolic dysfunction. Point-of-care ultrasound findings prompted expedited evaluation and management of this critically ill patient.

Paediatric dilated cardiomyopathy with and without endocardial fibroelastosis - a pathological analysis of 89 explants

Heart failure due to dilated cardiomyopathy is a major indication for paediatric cardiac transplantation. Endocardial fibroelastosis is a recognised pathological finding of unknown prognostic significance in paediatric dilated cardiomyopathy. To evaluate the nature of the association between left ventricular endocardial fibroelastosis and paediatric dilated cardiomyopathy, we reviewed surgical pathology reports of dilated cardiomyopathy explants (1986-2016) in order to characterise the pathological findings and to compare and contrast their frequency among four age groups: less than 1 year; 1-5 years; 6-10 years; and greater than 11 years. The 89 explants (47 males and 42 females) were all characterised by increased weight and left ventricular chamber dilatation without increased wall thickness. Ninety-five per cent of the specimens in the two youngest subsets had left ventricular endocardial fibroelastosis. Compared to the oldest age group, recipients aged 1-5 years had a 6-fold increase and those younger than 1 year a 19-fold increase in the odds of observing left ventricular endocardial fibroelastosis. Explants with and without endocardial fibroelastosis were otherwise phenotypically similar. In paediatric dilated cardiomyopathy endocardial fibroelastosis is a very common pathological finding, especially in infants and young children. We propose that the descriptive, clinico-pathological designation "Dilated Cardiomyopathy with Endocardial Fibroelastosis" should be adopted to facilitate future investigation into the potential prognostic/therapeutic significance of left ventricular endocardial fibroelastosis.

Development of Cardiac Events and Functional Recovery Prediction Models for Pediatric Dilated Cardiomyopathy

Background: Since both the risk of death and the probability of spontaneous functional recovery (FR) coexist in association with pediatric dilated cardiomyopathy (DCMP), management should be based on individualized outcome predictions. Methods: A single-center retrospective review of 105 pediatric patients (age at presentation ≤ 18 years) with DCMP, managed between 1994 and 2017, was performed. Logistic regression was conducted to identify variables associated with FR and cardiac events (CEs), i.e., death or heart transplantation (HTPL), within 2 years after initial presentation. Two outcome prediction models were formulated using these variables. Results: Twenty-six (24.8%) and 51 patients (48.6%) experienced FR and CE, respectively, within 2 years after initial presentation. Predictors of mortality without HTPL were earlier era at presentation (HR: 4.13; 95% CI: 1.88-9.06; p < 0.001) and significant TR (≥moderate; HR: 4.31; 95% CI: 1.26-14.77; p = 0.020) in multivariable Cox regression model. Predictors of FR were recent era (HR: 4.49; 95% CI: 1.40-14.44; p = 0.0012), younger age at initial presentation (HR: 0.98 per 1 month increase; 95% CI: 0.97-0.99, p < 0.001), post-myocarditis DCMP (HR: 4.29; 95% CI: 1.32-13.93; p = 0.015), and arrhythmia-mediated DCMP (HR: 26.88; 95% CI: 2.61-276.70; p = 0.006). Risk factors for CEs was idiopathic DCMP (HR: 2.95; 95% CI: 1.32-6.56, p = 0.008). The low-risk group who had higher probability of FR than CE in prediction model had a slightly higher overall survival rate (71.4 vs. 52.2% at 10 years after presentation; log-rank p = 0.09) and a significantly higher HTPL-free survival rate (67.5 vs. 24.9% at 10 years after presentation; log-rank p < 0.001) than the high-risk group. Conclusions: Prognostication and management strategies for pediatric DCMP may be enhanced by risk stratification using outcome prediction modeling.

Pulmonary Artery Banding for Ventricular Rehabilitation in Infants With Dilated Cardiomyopathy: Early Results in a Single-Center Experience

Background: Pulmonary artery banding (PAB) is reported as an innovative strategy for children with end-stage heart failure (ESHF) to bridge to transplantation or recovery. We report our early experience with PAB to evaluate outcomes, indications, and limitations. Materials and Methods: This is a single-center prospective clinical study, including infants and children admitted for ESHF owing to dilated cardiomyopathy (DCM) with preserved right ventricular function after failure of maximal conventional therapy. All patients underwent perioperative anticongestive medical therapy with ACE inhibitor, beta blocker, and spironolactone. Post-operatively, all patients underwent echocardiographic follow-up to assess myocardial recovery. Results: We selected five patients (four males) who underwent PAB at a median age of 8.6 months (range 3.9-42.2 months), with preoperative ejection fraction (EF) <30%. Sternal closure was delayed in all. One patient did not improve after PAB and underwent Berlin Heart implantation after 33 days, followed by heart transplant after 13 months. Four patients were discharged home on full anticongestive therapy. However, 2 months after discharge, one patient experienced severe acute heart failure secondary to pneumonia, which required mechanical circulatory support, and the patient underwent a successful heart transplant after 21 days. The remaining three patients are doing well at home, 22.4, 16.9, and 15.4 months after PAB. They all underwent elective percutaneous de-banding, 18.5, 4.8, and 10.7 months after PAB. EF increased from 17.7 ± 8.5% to 63.3 ± 7.6% (p = 0.03), and they have all been delisted. Conclusion: Use of PAB may be an effective alternative to mechanical support in selected infants for bridging to transplant or recovery. Better results seem to occur in patients aged <12 months. Further experience and research are required to identify responders and non-responders to this approach.

Effects of pulmonary artery banding in doxorubicin-induced left ventricular cardiomyopathy

OBJECTIVE

Central pulmonary banding has been proposed as a novel alternative for the treatment of left ventricular dilated cardiomyopathy in children. We sought to investigate the effects of central pulmonary banding in an experimental model of doxorubicin-induced left ventricular dilated cardiomyopathy.

METHODS

Four-month-old sheep (n = 28) were treated with intermittent intracoronary injections of doxorubicin (0.75 mg/kg/dose) into the left main coronary artery. A total dose of up to 2.15 mg/kg of doxorubicin was administered until signs of left ventricular dilation with functional impairment occurred by transthoracic echocardiography evaluation. Animals that survived were treated with surgical central pulmonary banding through a left anterior thoracotomy or sham surgery. Transthoracic echocardiography and pressure-volume loop measurements were used to compare left ventricular function preoperatively and 3 months later. Macroscopic and microscopic histologic examinations followed after hearts were harvested.

RESULTS

Nine animals from the central pulmonary banding group and 8 animals from the sham group survived and were included in the final analysis. Both groups showed similar inflammation and fibrosis upon histologic examination consistent with the toxic myocardial effects of doxorubicin. There were no differences in the echocardiographic measurements before central pulmonary banding or sham operation. Baseline measurements before the central pulmonary banding/sham operation were considered as 100%. The central pulmonary banding group had better left ventricular ejection fraction (102.5% ± 21.6% vs 76.7% ± 11.7%, P = .01), with a tendency for smaller left ventricular end-diastolic (101.2% ± 7.4% vs 120.4% ± 10.8%, P = .18) and significantly smaller end-systolic (100.3% ± 12.9% vs 116.5 ± 9.6%, P = .02) diameter of the left ventricle in comparison with the sham animals at 3 months. The end-systolic volume (101.4% ± 31.6% vs 143.4% ± 28.6%, P = .02) was significantly lower in the central pulmonary banding group 3 months postoperatively. Fractional shortening in the long axis (118.5% ± 21.5% vs 85.2% ± 22.8%, P = .016) and short axis (122.5% ± 18% vs 80.9% ± 13.6%, P = .0005) revealed significantly higher values in the central pulmonary banding group. In the conductance catheter measurements, no significant differences were seen between the groups for the parameters of systolic and diastolic function.

CONCLUSIONS

Central pulmonary artery banding in the setting of experimental toxic left ventricular dilated cardiomyopathy improved left ventricular echocardiographic function and dimensions.

Application of Neonatologist Performed Echocardiography in the Assessment and Management of Neonatal Heart Failure unrelated to Congenital Heart Disease

Neonatal heart failure (HF) is a progressive disease caused by cardiovascular and non-cardiovascular abnormalities. The most common cause of neonatal HF is structural congenital heart disease, while neonatal cardiomyopathy represents the most common cause of HF in infants with a structurally normal heart. Neonatal cardiomyopathy is a group of diseases manifesting with various morphological and functional phenotypes that affect the heart muscle and alter cardiac performance at, or soon after birth. The clinical presentation of neonates with cardiomyopathy is varied, as are the possible causes of the condition and the severity of disease presentation. Echocardiography is the selected method of choice for diagnostic evaluation, follow-up and analysis of treatment results for cardiomyopathies in neonates. Advances in neonatal echocardiography now permit a more comprehensive assessment of cardiac performance that could not be previously achieved with conventional imaging. In this review, we discuss the current and emerging echocardiographic techniques that aid in the correct diagnostic and pathophysiological assessment of some of the most common etiologies of HF that occur in neonates with a structurally normal heart and acquired cardiomyopathy and we provide recommendations for using these techniques to optimize the management of neonate with HF.

Survival Without Cardiac Transplantation Among Children With Dilated Cardiomyopathy

BACKGROUND

Studies of children with dilated cardiomyopathy (DCM) have suggested that improved survival has been primarily due to utilization of heart transplantation.

OBJECTIVES

This study sought to determine transplant-free survival for these children over 20 years and identify the clinical characteristics at diagnosis that predicted death.

METHODS

Children <18 years of age with some type of DCM enrolled in the Pediatric Cardiomyopathy Registry were divided by year of diagnosis into an early cohort (1990 to 1999) and a late cohort (2000 to 2009). Competing risks and multivariable modeling were used to estimate the cumulative incidence of death, transplant, and echocardiographic normalization by cohort and to identify the factors associated with death.

RESULTS

Of 1,953 children, 1,199 were in the early cohort and 754 were in the late cohort. Most children in both cohorts had idiopathic DCM (64% vs. 63%, respectively). Median age (1.6 vs. 1.7 years), left ventricular end-diastolic z-scores (+4.2 vs. +4.2), and left ventricular fractional shortening (16% vs. 17%) at diagnosis were similar between cohorts. Although the rates of echocardiographic normalization (30% and 27%) and heart transplantation (24% and 24%) were similar, the death rate was higher in the early cohort than in the late cohort (18% vs. 9%; p = 0.04). Being in the early cohort (hazard ratio: 1.4; 95% confidence interval: 1.04 to 1.9; p = 0.03) independently predicted death.

CONCLUSIONS

Children with DCM have improved survival in the more recent era. This appears to be associated with factors other than heart transplantation, which was equally prevalent in both eras. (Pediatric Cardiomyopathy Registry [PCMR]; NCT00005391).

Dilated cardiomyopathy

Dilated cardiomyopathy is defined by the presence of left ventricular dilatation and contractile dysfunction. Genetic mutations involving genes that encode cytoskeletal, sarcomere, and nuclear envelope proteins, among others, account for up to 35% of cases. Acquired causes include myocarditis and exposure to alcohol, drugs and toxins, and metabolic and endocrine disturbances. The most common presenting symptoms relate to congestive heart failure, but can also include circulatory collapse, arrhythmias, and thromboembolic events. Secondary neurohormonal changes contribute to reverse remodelling and ongoing myocyte damage. The prognosis is worst for individuals with the lowest ejection fractions or severe diastolic dysfunction. Treatment of chronic heart failure comprises medications that improve survival and reduce hospital admission-namely, angiotensin converting enzyme inhibitors and β blockers. Other interventions include enrolment in a multidisciplinary heart failure service, and device therapy for arrhythmia management and sudden death prevention. Patients who are refractory to medical therapy might benefit from mechanical circulatory support and heart transplantation. Treatment of preclinical disease and the potential role of stem-cell therapy are being investigated.

Intramuscular injection of human umbilical cord-derived mesenchymal stem cells improves cardiac function in dilated cardiomyopathy rats

Background

Stem cells provide a promising candidate for the treatment of the fatal pediatric dilated cardiomyopathy (DCM). This study aimed to investigate the effects of intramuscular injection of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) on the cardiac function of a DCM rat model.

Methods

A DCM model was established by intraperitoneal injections of doxorubicin in Sprague-Dawley rats. hUCMSCs at different concentrations or cultured medium were injected via limb skeletal muscles, with blank medium injected as the control. The rats were monitored for 4 weeks, meanwhile BNP, cTNI, VEGF, HGF, GM-CSF, and LIF in the peripheral blood were examined by ELISA, and cardiac function was monitored by echocardiography (Echo-CG). Finally, the expression of IGF-1, HGF, and VEGF in the myocardium was examined by histoimmunochemistry and real-time PCR, and the ultrastructure of the myocardium was examined by electron microscopy.

Results

Injection of hUCMSCs markedly improved cardiac function in the DCM rats by significantly elevating left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS). The BNP and cTNI levels in the peripheral blood were reduced by hUCMSCs, while HGF, LIF, GM-CSF, and VEGF were increased by hUCMSCs. Expression of IGF-1, HGF, and VEGF in the myocardium from the DCM rats was significantly increased by hUCMSC injection. Furthermore, hUCMSCs protected the ultrastructure of cardiomyocytes by attenuating mitochondrial swelling and maintaining sarcolemma integrity.

Conclusions

Intramuscular injection of UCMSCs can improve DCM-induced cardiac function impairment and protect the myocardium. These effects may be mediated by regulation of relevant cytokines in serum and the myocardium.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0472-y) contains supplementary material, which is available to authorized users.

Prevalence, predictors, and outcomes of cardiorenal syndrome in children with dilated cardiomyopathy: a report from the Pediatric Cardiomyopathy Registry

BACKGROUND

The association of cardiorenal syndrome (CRS) with mortality in children with dilated cardiomyopathy (DCM) is unknown.

METHODS

With a modified Schwartz formula, we estimated glomerular filtration rates (eGFR) for children ≥1 year of age with DCM enrolled in the Pediatric Cardiomyopathy Registry at the time of DCM diagnosis and annually thereafter. CRS was defined as an eGFR of <90 mL/min/1.73 m(2). Children with and without CRS were compared on survival and serum creatinine concentrations (SCr). The association between eGFR and echocardiographic measures was assessed with linear mixed-effects regression models.

RESULTS

Of 285 eligible children with DCM diagnosed at ≥1 year of age, 93 were evaluable. CRS was identified in 57 of these 93 children (61.3%). Mean (standard deviation) eGFR was 62.0 (22.6) mL/min/1.73 m(2) for children with CRS and 108.0 (14.0) for those without (P < 0.001); median SCr concentrations were 0.9 and 0.5 mg/dL, respectively (P < 0.001). The mortality hazard ratio of children with CRS versus those with no CRS was 2.4 (95% confidence interval 0.8-7.4). eGFR was positively correlated with measures of left ventricular function and negatively correlated with age.

CONCLUSIONS

CRS in children newly diagnosed with DCM may be associated with higher 5-year mortality. Children with DCM, especially those with impaired left ventricular function, should be monitored for renal disease.

Variability of M-mode versus two-dimensional echocardiography measurements in children with dilated cardiomyopathy

M-mode and 2-dimensional (2D) echocardiographic imaging are routinely used to quantify left-ventricular (LV) size and function in pediatric patients with dilated cardiomyopathy (DCM). The reproducibility of and correlation between these techniques are unknown. This analysis sought to compare interreader, intrareader, and interacquisition reproducibility of M-mode versus 2D measurements in pediatric DCM patients. The Ventricular Volume Variability study of the Pediatric Heart Network is a multicenter, prospective, observational study assessing the course of chronic DCM in children. Two sonographers performed baseline image acquisitions locally, and two readers performed measurements at the echocardiographic core laboratory. One reader repeated measurements 1 month later. These data were used to assess reproducibility and agreement between M-mode and 2D measurements. One hundred sixty-nine subjects were enrolled. M-mode had similar or greater reproducibility in both intrareader and interreader settings for LV dimensions, shortening fraction (SF), and most wall thicknesses. In contrast, 2D reproducibility was similar or better for nearly all variables in the interacquisition setting but not for SF. Interacquisition variability was approximately twice the intrareader variability. LV dimensions by either modality consistently had high reproducibility and had the highest agreement between modalities. In pediatric DCM patients, variability of linear echocardiographic assessment could be minimized by relying on a single reader and using a consistent method (M-mode or 2D) for serial measurements, preferably M-mode when SF is the primary variable of interest. Except for LV dimensions, M-mode and 2D values should not be used interchangeably due to poor agreement.

Role of cardiac magnetic resonance in the evaluation of dilated cardiomyopathy: diagnostic contribution and prognostic significance

Dilated cardiomyopathy (DCM) represents the final common morphofunctional pathway of various pathological conditions in which a combination of myocyte injury and necrosis associated with tissue fibrosis results in impaired mechanical function. Recognition of the underlying aetiology of disease and accurate disease monitoring may be crucial to individually optimize therapeutic strategies and stratify patient's prognosis. In this regard, CMR has emerged as a new reference gold standard providing important information for differential diagnosis and new insight about individual risk stratification. The present review article will focus on the role of CMR in the evaluation of present condition, analysing respective strengths and limitations in the light of current literature and technological developments.

Cardiomyopathies encountered commonly in the teenage years and their presentation

Cardiomyopathy encompasses a broad range of inherited and acquired abnormalities affecting the myocardium. This heterogeneous group of disorders is an important cause of morbidity and mortality in the adolescent patient as a result of the presence of systolic or diastolic dysfunction, as well as the risk of coexisting arrhythmias and sudden cardiac death. It is important for the primary care physician involved in the care of adolescents to understand the different causes of cardiomyopathy and their typical clinical presentations. The cause, pathogenesis, clinical presentation, and diagnostic evaluation for adolescents with cardiomyopathy are reviewed. An overview of treatment modalities is also presented.

Predictors of disease progression in pediatric dilated cardiomyopathy

BACKGROUND

Despite medical advances, children with dilated cardiomyopathy (DCM) remain at high risk of death or need for cardiac transplantation. We sought to identify predictors of disease progression in pediatric DCM.

METHODS AND RESULTS

The Pediatric Heart Network evaluated chronic DCM patients with prospective echocardiographic and clinical data collection during an 18-month follow-up. Inclusion criteria were age <22 years and DCM disease duration >2 months. Patients requiring intravenous inotropic/mechanical support or listed status 1A/1B for transplant were excluded. Disease progression was defined as an increase in transplant listing status, hospitalization for heart failure, intravenous inotropes, mechanical support, or death. Predictors of disease progression were identified using Cox proportional hazards modeling and classification and regression tree analysis. Of the 127 patients, 28 (22%) had disease progression during the 18-month follow-up. Multivariable analysis identified older age at diagnosis (hazard ratio=1.14 per year; P<0.001), larger left ventricular (LV) end-diastolic M-mode dimension z-score (hazard ratio=1.49; P<0.001), and lower septal peak systolic tissue Doppler velocity z-score (hazard ratio=0.81; P=0.01) as independent predictors of disease progression. Classification and regression tree analysis stratified patients at risk of disease progression with 89% sensitivity and 94% specificity based on LV end-diastolic M-mode dimension z-score ≥7.7, LV ejection fraction <39%, LV inflow propagation velocity (color M-mode) z-score <-0.28, and age at diagnosis ≥8.5 months.

CONCLUSIONS

In children with chronic stable DCM, a combination of diagnosis after late infancy and echocardiographic parameters of larger LV size and systolic and diastolic function predicted disease progression.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00123071.

A comparison of heart rate changes associated with levalbuterol and racemic albuterol in pediatric cardiology patients

BACKGROUND

To our knowledge, no data exist regarding the effect of levalbuterol and racemic albuterol on heart rate in pediatric cardiology patients.

OBJECTIVE

To compare heart rate change in pediatric cardiology patients receiving levalbuterol and/or racemic albuterol. The secondary objective was to identify characteristics associated with heart rate changes observed with these drugs.

METHODS

A review of electronic medical records at a pediatric academic hospital was conducted to determine the equivalence of heart rate change in patients receiving levalbuterol or racemic albuterol. Patients receiving at least 3 doses of levalbuterol and/or racemic albuterol during the study period were included if they were younger than 18 years and had a diagnosis of congenital heart disease (CHD), cardiomyopathy, or supraventricular tachycardia. Patients were excluded if they received a β-blocker or continuous racemic albuterol or did not have documented pre- and postdose heart rates.

RESULTS

One hundred ninety-two patients were included. One hundred forty-two received racemic albuterol, 40 received levalbuterol, and 10 received both racemic albuterol and levalbuterol. The mean increase in heart rate for patients receiving racemic albuterol and levalbuterol was 6.8 beats/min and 6.2 beats/min, respectively (p = 0.01). In patients with CHD, the racemic albuterol group experienced a mean heart rate increase of 6.6 beats/min compared to 6.3 beats/min in the levalbuterol group (p = 0.01). Equivalence was also determined in patients without surgical intervention and patients receiving concomitant cardiac and respiratory medications. Equivalence was not established in other analyzed subgroups secondary to insufficient sample sizes.

CONCLUSIONS

Racemic albuterol and levalbuterol were associated with increased heart rate in pediatric cardiology patients. This increase was found to be equivalent.

Abdominal complaints as a common first presentation of heart failure in adolescents with dilated cardiomyopathy

OBJECTIVE

We hypothesized that isolated gastrointestinal complaints (abdominal pain, nausea, anorexia, weight loss), in the absence of other symptoms, were a common mode of initial presentation in children with congestive heart failure (CHF).

STUDY DESIGN

Ninety-eight patients younger than 18 years hospitalized with dilated cardiomyopathy at a single institution between January 1, 2000, and December 31, 2009, were included. Retrospective review of their presenting complaints was recorded and analyzed according to 3 age groups: 0 to 1 year (infants), 1 to 10 years (children), and 11 to 18 years (adolescents) of age.

RESULTS

Respiratory symptoms were common in all age groups (range, 56%-63%). Gastrointestinal complaints were also common in all age groups (42%, 28%, and 65%, respectively) and were more frequent than respiratory complaints in adolescents. Adolescents were likely to present with abdominal pain as their only complaint (10/43, 23%). Chest pain, syncope, or cardiac arrest occurred rarely.

CONCLUSIONS

Abdominal complaints are a common component of the presenting symptom complex of CHF in pediatric dilated cardiomyopathy in all age groups. In adolescents, abdominal complaints occur more frequently than respiratory complaints and often in the absence of any other symptoms. Unlike CHF in adults, chest pain, arrhythmia, or cardiac arrest occurs rarely at presentation in pediatric patients. Recognition of the different presenting symptoms of heart failure in children by primary providers is crucial to ensuring prompt diagnosis and timely initiation of therapy.

Early predictors of survival to and after heart transplantation in children with dilated cardiomyopathy

BACKGROUND

The importance of clinical presentation and pretransplantation course on outcome in children with dilated cardiomyopathy listed for heart transplantation is not well defined.

METHODS AND RESULTS

The impact of age, duration of illness, sex, race, ventricular geometry, and diagnosis of myocarditis on outcome in 261 children with dilated cardiomyopathy enrolled in the Pediatric Cardiomyopathy Registry and Pediatric Heart Transplant Study was studied. End points included listing as United Network for Organ Sharing status 1, death while waiting, and death after transplantation. The median age at the time of diagnosis was 3.4 years, and the mean time from diagnosis to listing was 0.62±1.3 years. Risk factors associated with death while waiting were ventilator use and older age at listing in patients not mechanically ventilated (P=0.0006 and P=0.03, respectively). Shorter duration of illness (P=0.04) was associated with listing as United Network for Organ Sharing status 1. Death after transplantation was associated with myocarditis at presentation (P=0.009), nonwhite race (P<0.0001), and a lower left ventricular end-diastolic dimension z score at presentation (P=0.04). In the myocarditis group, 17% (4 of 23) died of acute rejection after transplantation.

CONCLUSIONS

Mechanical ventilator use and older age at listing predicted death while waiting, whereas nonwhite race, smaller left ventricular dimension, and myocarditis were associated with death after transplantation. Although 97% of children with clinically or biopsy-diagnosed myocarditis at presentation survived to transplantation, they had significantly higher posttransplantation mortality compared with children without myocarditis, raising the possibility that preexisting viral infection or inflammation adversely affects graft survival.

The mutations associated with dilated cardiomyopathy

Cardiomyopathy is an important cause of heart failure and a major indication for heart transplantation in children and adults. This paper describes the state of the genetic knowledge of dilated cardiomyopathy (DCM). The identification of the causing mutation is important since presymptomatic interventions of DCM have proven value in preventing morbidity and mortality. Additionally, as in general in genetic studies, the identification of the mutated genes has a direct clinical impact for the families and population involved. Identifying causative mutations immediately amplifies the possibilities for disease prevention through carrier screening and prenatal testing. This often lifts a burden of social isolation from affected families, since healthy family members can be assured of having healthy children. Identification of the mutated genes holds the potential to lead to the understanding of disease etiology, pathophysiology, and therefore potential therapy. This paper presents the genetic variations, or disease-causing mutations, contributing to the pathogenesis of hereditary DCM, and tries to relate these to the functions of the mutated genes.

Outcomes of children following a first hospitalization for dilated cardiomyopathy

BACKGROUND

We hypothesized that children with dilated cardiomyopathy who require hospital admission are at increased risk for death or transplantation during their first hospitalization and in the first year that follows. We also assessed the value of routine data collected during that time to predict death or the need for transplantation prior to discharge and within 1 year of admission.

METHODS AND RESULTS

We conducted a retrospective review of 83 pediatric patients with dilated cardiomyopathy whose initial hospitalization fell between 2004 and 2009. The mean age at hospitalization was 7 years. The majority of patients demonstrated moderate or severe left ventricular dysfunction on initial echocardiogram (80%) and/or the need for intravenous inotropes within 7 days of hospital admission (69%). Five patients (6%) died, and 15 (18%) were transplanted in the initial hospitalization. At 1 year, 11/71 (15%) had died, and 27/71 (38%) were transplanted. The overall freedom from death, transplantation, or rehospitalization at 1 year following admission was 21%. Fractional shortening, left ventricular ejection fraction, serum cholesterol, uric acid, mixed venous saturation, and atrial filling pressures were all predictive of death or transplantation during the initial hospitalization. Left ventricular ejection fraction was predictive of death or transplantation at 1 year.

CONCLUSIONS

The first hospitalization for dilated cardiomyopathy marks a period of high risk for clinical decline, end stage heart failure, and the need for cardiac transplantation. Echocardiographic function and hemodynamic and serum measurements may aid in predicting outcomes. Despite medical management, most patients will be rehospitalized and/or require cardiac transplantation within 1 year of admission.