Implantable Cardioverter Defibrillators in Infants and Toddlers: Indications, Placement, Programming, and Outcomes.

Background: Limited data exist regarding implantable cardioverter defibrillator (ICD) usage in infants and toddlers. This study evaluates ICD placement indications, procedural techniques, programming strategies, and outcomes of ICDs in infants and toddlers.

Methods: This is a single-center retrospective review of all patients ≤3 years old who received an ICD from 2009 to 2021.

Single Ventricular Assist Device Support for the Failing Bidirectional Glenn Patient.

Background: Given poor outcomes, strategies to improve ventricular assist devices (VADs) for single-ventricle patients with bidirectional Glenn (BDG) palliation are needed.

Methods: This retrospective review describes an institutional experience with VAD support for patients with BDG from April 2011 to January 2019. Surgical strategies, complications, and causes of death are described.

Aortic or Pulmonary Valved Homograft Right Ventricle to Pulmonary Artery Conduit in the Norwood Procedure.

Background: Several modifications of the Norwood procedure utilizing valved right ventricle to pulmonary artery conduits have recently been reported. Our group has been using aortic or pulmonary valved homografts combined with PTFE tube grafts for now 16 years.

Methods: In this report, we review our technique in detail and describe any changes that have occurred over the years.

Bridge to Transplant with Ventricular Assist Device Support in Pediatric Patients with Single Ventricle Heart Disease.

Ventricular assist device (VAD) support for children with single ventricle (SV) heart disease remains challenging. We performed a single-center retrospective review of SV patients on VAD support and examined survival to transplant using the Kaplan-Meier method. Patients transplanted were compared with those who died on support.

Patient-Specific Multiscale Modeling of the Assisted Bidirectional Glenn.

Background: First-stage palliation of neonates with single-ventricle physiology is associated with poor outcomes and challenging clinical management. Prior computational modeling and in vitro experiments introduced the assisted bidirectional Glenn (ABG), which increased pulmonary flow and oxygenation over the bidirectional Glenn (BDG) and the systemic-to-pulmonary shunt in idealized models. In this study, we demonstrate that the ABG achieves similar performance in patient-specific models and assess the influence of varying shunt geometry.

Characteristics of deposits and pump exchange in the Berlin Heart EXCOR ventricular assist device: Experience with 67 cases.

Pump exchanges are frequently required in the Berlin Heart EXCOR VAD. We intended to describe the characteristics of pump deposits in a larger patient series and evaluate if changes in our exchange procedure over time have led to increased complications. We reviewed all EXCOR pump exchanges in our institution from July 2004 to October 2014.

Ventricular Assist Devices for Neonates and Infants.

Heart transplant waitlist survival in pediatric patients has been substantially improved since the introduction of pediatric-specific ventricular assist device. In neonates and infants, however, the waitlist mortality remains very high. The only long-term device currently approved for use in the United States is the Berlin Heart EXCOR, but this device has several important limitations because of the paracorporeal, pulsatile nature of the underlying technology.

Interstage evaluation of homograft-valved right ventricle to pulmonary artery conduits for palliation of hypoplastic left heart syndrome.

Objective: Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling.

Methods: This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015.

Effect of Inhaled Nitric Oxide on Hemodynamics in Lambs with 1½ Ventricle Circulation.

Inhaled nitric oxide (NO) is widely used to treat postoperative pulmonary hypertension in congenital heart disease. It is believed that NO increases cardiac output (CO) by decreasing pulmonary vascular resistance (PVR), leading to increased left ventricular preload. However, the effect of NO on CO in patients with 1½ ventricle circulation remains unclear.

Temporary Circulatory Support in U.S. Children Awaiting Heart Transplantation.

Background: Extracorporeal membrane oxygenation (ECMO) has long served as the standard of care for short-term mechanical circulatory support in pediatrics. It is unknown whether newer-generation temporary circulatory support (TCS) devices afford children a meaningful survival advantage over ECMO.

Objectives: This study sought to determine whether bridge-to-heart transplant survival with a TCS device is superior to ECMO after adjusting for patient differences.

Alternative Strategy for Biventricular Assist Device in an Infant With Hypertrophic Cardiomyopathy.

We report an infant with hypertrophic cardiomyopathy who underwent biventricular assist device placement with two 15-mL Berlin Heart EXCOR pediatric ventricular assist devices using an alternative atrial cannulation strategy. The systemic circulation was supported by left atrium (LA) to aorta cannulation. The LA was accessed through the right atrium by extending a 6-mm EXCOR cannula with a Gore-Tex graft connected to an atrial septal defect.

Impact of a modified anti-thrombotic guideline on stroke in children supported with a pediatric ventricular assist device.

Background: Stroke is the most feared complication associated with the Berlin Heart EXCOR pediatric ventricular assist device (VAD), the most commonly used VAD in children, and affects 1 in 3 children. We sought to determine whether a modified anti-thrombotic guideline, involving more intense platelet inhibition and less reliance on platelet function testing, is associated with a lower incidence of stroke.

Methods: All children supported with the EXCOR at Stanford from 2009 to 2014 were divided into 2 cohorts based on the primary anti-thrombotic guideline used to prevent pump thrombosis: (1) the Edmonton Anti-thrombotic Guideline (EG) cohort, which included children implanted before September 2012 when dual anti-platelet therapy was used with doses titrated to Thromboelastrography/PlateletMapping (TEG/PM); and (2) the Stanford Modified Anti-thrombotic Guideline (SG) cohort, which included children implanted on or after September 2012 when triple anti-platelet therapy was used routinely and where doses were uptitrated to high, weight-based dosing targets, with low-dose steroids administered as needed for inflammation.

Major Aortopulmonary Collateral Arteries With Anatomy Other Than Pulmonary Atresia/Ventricular Septal Defect.

Background: Major aortopulmonary collateral arteries (MAPCAs) are frequently found in association with pulmonary atresia with ventricular septal defect (PA/VSD). However, some patients with MAPCAs do not have PA/VSD but have a variety of other "atypical" anatomic diagnoses.

Methods: This was a retrospective review of patients with MAPCAs and atypical anatomy.

Functional status of United States children supported with a left ventricular assist device at heart transplantation.

Background: As survival with pediatric left ventricular assist devices (LVADs) has improved, decisions regarding the optimal support strategy may depend more on quality of life and functional status (FS) rather than mortality alone. Limited data are available regarding the FS of children supported with LVADs. We sought to compare the FS of children supported with LVADs vs vasoactive infusions to inform decision making around support strategies.

Superior performance of continuous over pulsatile flow ventricular assist devices in the single ventricle circulation: A computational study.

This study compares the physiological responses of systemic-to-pulmonary shunted single ventricle patients to pulsatile and continuous flow ventricular assist devices (VADs). Performance differences between pulsatile and continuous flow VADs have been clinically observed, but the underlying mechanism remains poorly understood. Six systemic-to-pulmonary shunted single ventricle patients (mean BSA=0.

Outcomes of pediatric patients supported with continuous-flow ventricular assist devices: A report from the Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS).

Background: Continuous-flow (CF) ventricular assist devices (VADs) have largely replaced pulsatile-flow VADs in adult patients. However, there are few data on CF VADs among pediatric patients. In this study we aimed to describe the overall use, patients' characteristics and outcomes of CF VADs in this population.

HeartWare HVAD for Biventricular Support in Children and Adolescents: The Stanford Experience.

Despite increasing use of mechanical circulatory support in children, experience with biventricular device implantation remains limited. We describe our experience using the HeartWare HVAD to provide biventricular support to three patients and compare these patients with five patients supported with HeartWare left ventricular assist device (LVAD). At the end of the study period, all three biventricular assist device (BiVAD) patients had been transplanted and were alive.

Outpatient Outcomes of Pediatric Patients with Left Ventricular Assist Devices.

Outpatient experience of children supported with continuous-flow ventricular assist devices (CF-VAD) is limited. We reviewed our experience with children discharged with CF-VAD support. All pediatric patients <18 years old with CF-VADs implanted at our institution were included.

Anatomic Factors Associated With Truncal Valve Insufficiency and the Need for Truncal Valve Repair.

Purpose: Truncus arteriosus is a complex and heterogeneous form of congenital heart defect. Many of the risk factors from several decades ago, including late repair and interrupted aortic arch, have been mitigated through better understanding of the entity and improved surgical techniques. However, truncal valve dysfunction remains an important cause of morbidity and mortality.

Changes in Risk Profile Over Time in the Population of a Pediatric Heart Transplant Program.

Background: Single-center data on pediatric heart transplantation spanning long time frames is sparse. We attempted to analyze how risk profile and pediatric heart transplant survival outcomes at a large center changed over time.

Methods: We divided 320 pediatric heart transplants done at Stanford University between 1974 and 2014 into three groups by era: the first 20 years (95 transplants), the subsequent 10 years (87 transplants), and the most recent 10 years (138 transplants).

Ventricular assist devices in a contemporary pediatric cohort: Morbidity, functional recovery, and survival.

Background: Limited availability of donor organs has led to the use of ventricular assist devices (VADs) to treat heart failure in pediatric patients, primarily as bridge to transplantation. How effective VAD therapy is in promoting functional recovery in children is currently not known.

Methods: We report morbidity and mortality as defined by the Interagency Registry for Mechanically Assisted Circulatory Support Modified for Pediatrics (PediMACS) and the use of the Treatment Intensity Score to assess functional status for 50 VAD patients supported at a single pediatric program from 2004 to 2013.

Elevated pretransplant pulmonary vascular resistance index does not predict mortality after isolated orthotopic heart transplantation in children: A retrospective analysis of the UNOS database.

OHT is the definitive therapy in end-stage heart failure. Elevated PVRI is considered a relative contraindication to isolated OHT; this assumption is re-evaluated using data from the UNOS database. A retrospective review of de-identified data from the UNOS dataset was performed.

Is Continuous Flow Superior to Pulsatile Flow in Single Ventricle Mechanical Support? Results from a Large Animal Pilot Study.

Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented.

High-resolution coronary MR angiography for evaluation of patients with anomalous coronary arteries: visualization of the intramural segment.

Background: Anomalous origin of the coronary artery from the contralateral coronary sinus is a rare coronary anomaly associated with sudden death. The inter-arterial course is most closely associated with sudden death, but it has been suggested that the presence of an intramural segment of a right anomalous coronary is associated with more symptoms and therefore may be an important criterion for intervention in these patients.

Objective: To demonstrate that MR angiography can accurately determine the presence or absence of an intramural segment in an anomalous coronary artery.

Conserved and divergent aspects of human T-cell development and migration in humanized mice.

Humanized mice represent an important model to study the development and function of the human immune system. While it is known that mouse thymic stromal cells can support human T-cell development, the extent of interspecies cross-talk and the degree to which these systems recapitulate normal human T-cell development remain unclear. To address these questions, we compared conventional and non-conventional T-cell development in a neonatal chimera humanized mouse model with that seen in human fetal and neonatal thymus samples, and also examined the impact of a human HLA-A2 transgene expressed by the mouse stroma.