Matthew J. O’Connor

Early systemic-to-pulmonary artery shunt intervention in neonates with congenital heart disease

OBJECTIVE To determine the incidence, risk factors, and outcomes after early, unplanned intervention on systemic-to-pulmonary artery shunts in neonates. METHODS We retrospectively studied all neonates undergoing systemic-to-pulmonary artery shunt placement at The Childrens Hospital of Philadelphia between September 1, 2002, and May 1, 2005. Patients requiring transcatheter or surgical systemic-to-pulmonary artery shunt intervention before discharge were compared with those not undergoing shunt intervention. RESULTS A total of 206 patients underwent shunt placement. Diagnoses included hypoplastic left heart syndrome (62.1%), pulmonary atresia (15%), tricuspid atresia (4.9%), tetralogy of Fallot (2.4%), and other lesions with obstruction to systemic (10.7%) or pulmonary blood flow (4.9%). Twenty-one interventions occurred in 20 patients (9.7%). Risk factors for intervention included heterotaxy syndrome (P = .04), congenital abnormality (P = .04), and a trend toward lower birthweight. In patients with a modified Blalock-Taussig shunt, similar risk factors were identified and the incidence of intervention decreased with increasing shunt size. In-hospital mortality was 30% (6/20) for the cases and 8.1% (15/186) for the nonintervention group (P = .02). Long-term survival was significantly lower in patients requiring intervention (P = .002). This group also had a higher incidence of infections (P < .001) and extracorporeal membrane oxygenation (P < .001), and longer hospital stay (P = .001). CONCLUSIONS In neonates undergoing systemic-to-pulmonary artery shunt placement, approximately 10% underwent shunt intervention before discharge. Some factors, such as low birthweight, shunt size, noncardiac congenital abnormalities, and heterotaxy syndrome, may help identify patients at risk. Patients undergoing intervention experienced increased morbidity and mortality.

Ventricular assist devices in children.

Purpose of review Ventricular assist devices (VADs) have revolutionized heart failure management in adults. Recently, VADs have similarly taken a prominent role in the management of end-stage heart failure in children. The purpose of this review is to describe the indications for VADs in children, types of devices available, current outcomes, and future directions of VAD therapy. Recent findings There has been a dramatic increase in VAD utilization in children over the last decade. For small children, paracorporeal pneumatic pulsatile pumps (e.g., Berlin Heart EXCOR VAD, Berlin Heart GmbH, Berlin, Germany) are most commonly utilized for long-term support. In older children, intracorporeal continuous flow devices (e.g., HeartMate II Left Ventricular Assist System, Thoratec Corporation, Pleasanton, California, USA and HeartWare Ventricular Assist System, HeartWare Incorporated, Framingham, Massachusetts, USA) have been used and allow the possibility of destination therapy. Other devices, such as the total artificial heart, can be utilized for selected patients. Although overall outcomes of pediatric VADs are favorable, complication rates remain high. The utilization of VADs in complex circulations, such as single ventricle patients, remains infrequent and is associated with a high rate of adverse outcomes. Summary VADs are well-established treatment for end-stage heart failure in children. Further investigation is needed to refine patient selection criteria, minimize complications, and develop additional pediatric-specific devices.

Persistence of anti-human leukocyte antibodies in congenital heart disease late after surgery using allografts and whole blood

BACKGROUND Allografts are used for vascular reconstruction in many forms of congenital heart disease. Although allografts induce anti-human leukocyte antibody (HLA) formation, much about this response is unknown. METHODS Three groups of patients aged 8 to 18 years old underwent analysis for class I and II anti-HLA antibodies using Luminex. Groups were defined by timing of allograft exposure and diagnosis at Norwood for hypoplastic left heart syndrome (neonatal group), at Glenn for single-ventricle lesions not requiring arch reconstruction (infant group), and cardiac defects repaired during infancy without allografts (controls). Patients had significant anti-HLA (sensitization) if mean fluorescence intensity was ≥ 1500. RESULTS The study enrolled 29 patients (median age, 10.1 years). Significant class I anti-HLA antibodies were seen in 44% (8 of 18) of the neonatal group, 25% (1 of 4) of the infant group, and 14% (1 of 7) of controls; class II anti-HLA antibodies were seen in 44% (8 of 18) of the neonatal group, 25% (1 of 4) of the infant group, and 29% (2 of 7) of controls. All patients received fresh whole blood, but the neonatal group had greater exposure (p = 0.001). There was less sensitization with increasing time from last receipt of allograft(s) or blood transfusion (p = 0.05). CONCLUSIONS Exposure to allograft at the Norwood procedure is associated with long-term sensitization to anti-HLA antibodies in 56% of patients. Sensitization also occurs in those without prior exposure to allografts, may decrease over time, and appears related to whole blood. These findings have implications for those in whom heart transplant is considered late in the clinical course.

Contemporary management of congenital malformations of the heart in infants with Ellis - van Creveld syndrome: a report of nine cases.

INTRODUCTION Ellis - van Creveld syndrome is an autosomal recessive disorder manifest by short-limb dwarfism, thoracic dystrophy, postaxial polydactyly, dysplastic nails and teeth, and an approximately 60% incidence of congenital malformations of the heart. Despite patients with Ellis - van Creveld syndrome being regarded as having a high surgical risk, few data are available regarding their outcomes following surgery for congenital malformations of the heart in the current era. MATERIALS AND METHODS In this retrospective report, we summarise the clinical observations and outcomes of nine infants with Ellis - van Creveld syndrome who underwent surgery for congenital malformations of the heart between 2004 and 2009. RESULTS We identified 15 patients with Ellis - van Creveld syndrome during the study period; 11 (73%) had haemodynamically significant congenital malformations of the heart warranting surgery. In two of these patients, surgery was not performed. Of the nine patients who underwent surgery, all of whom were infants, eight (89%) had various forms of an atrioventricular septal defect and one patient (11%) had hypoplastic left heart syndrome (mitral and aortic atresia). Among the nine patients who underwent surgery, four (44%) died at a median of 102 days with a range of 25-149 days post-operatively, mostly from respiratory failure. Respiratory morbidity was seen in all surviving patients, of whom three underwent tracheostomy. CONCLUSIONS Surgery for congenital malformations of the heart can be successful in infants with Ellis - van Creveld syndrome, but mortality is high and post-operative respiratory morbidity should be expected.

Left Ventricular Rotational Mechanics in Children After Heart Transplantation

Background—Left ventricular (LV) dysfunction after orthotopic heart transplantation (OHT) is multifactorial and can be an indicator of graft rejection or coronary artery vasculopathy. Analysis of rotational mechanics may help in the early diagnosis of ventricular dysfunction. Studies describing the left ventricular rotational strain in children after OHT are lacking. It is important to establish the baseline rotational mechanics in pediatric OHT to pursue further studies in this population. Methods and Results—Rotational strain measured by speckle tracking was compared in 32 children after OHT, with no evidence of active rejection or coronary artery vasculopathy with 35 age-matched normal controls. Twelve OHT patients and 13 controls underwent moderate exercise with pre- and postexercise echocardiography. Torsion, slope of the systolic limb of the torsion–radial displacement loop, and the untwist rate were significantly higher in OHT patients (torsion: median 2.7°/cm [Q1–Q3, 2.3–3.2] versus 2.3°/cm [Q1–Q3, 1.9–2.7]; P=0.03, torsion–radial displacement loop: 2.7°/mm [Q1–Q3, 2.1–3.6] versus 2.0°/mm [Q1–Q3, 1.6–2.7]; P=0.008, indexed peak untwist rate: −21.6°/s/cm [Q1–Q3, −24.3 to −15.7] versus −17.1°/s/cm [Q1–Q3, −19.6 to −13.3]; P=0.01). Contrary to controls, OHT recipients were unable to increase torsion with exercise (OHT: 2.8°/cm [2.7–3.2] versus 3°/cm [2.4–3.5]; P=0.81, controls: 2.2°/cm [2–2.6] versus 3°/cm [2.4–3.7]; P=0.01, pre and post exercise, respectively). The systolic slope of the torsion–radial displacement loop relationship decreased with exercise in most OHT patients. Conclusions—Baseline rotational strain in OHT patients is higher than normal with a blunted response to exercise. The slope of torsion–radial displacement loop, and its response to exercise, may serve as a marker of left ventricular dysfunction in OHT patients.

Long-Term Outcomes of Pediatric Cardiac Patients Supported by Extracorporeal Membrane Oxygenation

Objective: Extracorporeal membrane oxygenation is an important form of short-term mechanical support in children with cardiac disease, but information on long-term outcomes and quality of life is limited. The primary objective of this study was to determine the long-term outcomes of children previously supported by extracorporeal membrane oxygenation for cardiac etiologies. Design: A retrospective analysis was performed on patients with cardiac disease managed with extracorporeal membrane oxygenation between January 1, 1995, and December 31, 2012, at the Children’s Hospital of Philadelphia. Survivors completed patient- and parent-reported verbal and written surveys, and univariate analyses assessed risk factors for long-term outcomes. Setting: Tertiary-care children’s hospital. Patients: Patients with cardiac disease managed with extracorporeal membrane oxygenation. Interventions: None. Measurements and Main Results: Over 18 years, 396 patients were managed with extracorporeal membrane oxygenation with 43% survival to discharge. The median age at cannulation was 78 days. The majority had congenital heart disease (86%), surgery prior to extracorporeal membrane oxygenation (71%), and cardiopulmonary arrest as the primary extracorporeal membrane oxygenation indication (53%). With 6-year median follow-up, 66% are known to be deceased, including 38 deaths after hospital discharge. Among survivors at discharge, 65 (38%) completed the phone survey, and 33 (19%) completed the written survey. Negative clinical outcomes, defined as having at least significant physical limitations or “fair” or “poor” health, were present in 18% of patients. No patient- or extracorporeal membrane oxygenation–related variables were associated with negative outcomes in univariate analyses. There were significantly lower self-reported and parent-reported written Pediatric Quality of Life Inventory quality of life scores in children compared with healthy individual normative data but no differences in adolescents. Conclusions: In this series of pediatric cardiac patients supported by extracorporeal membrane oxygenation, mortality was 66% with 6-year median follow-up. The majority reported positive outcomes with respect to health and physical limitations, but children reported lower quality of life compared with healthy individuals.

Recognizing, Stabilizing, and Managing Children with Heart Failure in the Emergency Department and Other Acute Care Settings

Heart failure is uncommon in children, but it often initially presents in acute care settings, such as the emergency department. As a result, clinicians need to be aware of its causes and common presenting symptoms, as well as basic principles of stabilization and management. The causes of heart failure in children vary by age, and many symptoms initially attributable to other organ systems may actually indicate heart failure. Here, we review the principles of recognizing, stabilizing, and managing pediatric heart failure in the emergency department.

Heart Failure in the Neonate

Abstract Neonatal heart failure is a clinical syndrome caused by cardiovascular and noncardiovascular abnormalities, which results in characteristic signs and symptoms including edema, respiratory distress, and growth failure accompanied by circulatory, neurohormonal, and molecular derangements. The causes of neonatal heart failure are varied and include congenital heart disease, inherited or acquired cardiomyopathy, and systemic diseases. Accurate diagnosis of etiology is key for appropriate therapy and is comprised of thorough evaluation, including family history, focused physical exam, noninvasive cardiac testing, laboratory testing, and, in appropriate cases, invasive testing including endomyocardial biopsy. Treatment options include diuretic therapy, afterload reduction, beta-blockade, inotropic and vasoactive medications, mechanical ventilatory and circulatory support, and heart transplantation. In the majority of instances, these treatment modalities have been described in adult or older pediatric populations and can only be extrapolated to the neonatal age-group.

RISK FACTORS FOR MORTALITY IN PEDIATRIC CARDIAC INTENSIVE CARE UNIT PATIENTS MANAGED WITH EXTRACORPOREAL MEMBRANE OXYGENATION IN A CONTEMPORARY COHORT

Extracorporeal membrane oxygenation (ECMO) utilization for children with cardiac disease has increased over the past 20 years, yet mortality remains high. In a previous study (1995-2001), we reported 39% survival to discharge. This study aims to report mortality for pediatric cardiac patients

Familial long QT syndrome and late development of dilated cardiomyopathy in a child with a KCNQ1 mutation: A case report

Congenital long QT syndrome (LQTS) is an inherited cardiac channelopathy characterized by prolongation of the QT interval on electrocardiogram (ECG), and is associated with an increased risk of life-threatening ventricular arrhythmias. Mutations in over a dozen distinct genes have been implicated in the pathogenesis of this group of disorders. LQTS type 1 (LQT1), the most prevalent LQTS subtype, is characterized by a heterozygous loss-of-function mutation in the KCNQ1 gene, which codes for the α-subunit of the delayed rectifier inward potassium ion channel. The association of LQTS with dilated cardiomyopathy (DCM) is rare but has been reported in the presence of sodium channel gene mutations, as seen in LQTS type 3. In this case report, we describe a patient with familial LQT1 (KCNQ1 mutation) identified in infancy who was subsequently diagnosed with severe DCM later in childhood.