Search

Background: Cardiac asthma describes symptoms of airflow obstruction due to heart failure. Chronic heart failure is associated with decreased FEV 1 , and FEV 1 improves after heart transplantation. Fibrotic remodeling of the heart and airways is mediated, in part, through transforming growth factor (TGF)- β . Blood TGF- b 1 concentration correlates with ventricular remodeling in cardiac disease, and TGF- β decreases after repair.Methods: We established a coculture of normal human bronchial epithelial (NHBE) cells differentiated at air-liquid interface with submerged basal cardiomyoblasts. Airway cells were immunostained with cytokeratin, actin, and involucrin. TGF- β synthesis was assayed using enzyme-linked immunosorbent assay. Phosphorylation of Smad in NHBE cells was determined by Western blotting.Mice given doxorubicin developed cardiac failure, and their airways were histologically examined.Results: Coculture induced involucrin-positive squamous metaplasia of NHBE cells, and this was attenuated by TGF- β antibody. Total TGF- β 1 was increased in coculture conditioned medium( P < .001). After 14 days of exposure to recombinant TGF- β 1 , there was squamous transformation of NHBE cells. One week after removing cardiomyoblasts from culture, squamous metaplasia resolved into normal ciliated epithelia. Smad was phosphorylated in NHBE cells with cardiomyoblasts or with recombinant TGF- β 1 exposure. The airways of mice with heart failure also demonstrated involucrin-positive squamous transformation.Conclusions: TGF- β from cardiomyoblasts or from the failing heart can cause airway squamous metaplasia via Smad signaling, and this is blocked by anti-TGF- b antibody and reversed when cardiac cells are removed from culture. This appears to be an important mechanism for airflow obstruction with heart failure, sometimes described as cardiac asthma. [ABSTRACT FROM AUTHOR]

This retrospective study included children aged ≤18 years who had durable ventricular assist devices (VADs) as a bridge to transplantation from the United Network Organ Sharing (UNOS) database between 2011 and 2020. We evaluated 90 day waitlist mortality and 1 year posttransplant mortality after VAD implantation in children stratified by race/ethnicity: Black, White, and Others. The VAD was used in a higher proportion of Black children listed for heart transplantation (HT) (26%) versus Other (25%) versus White (22%); p < 0.01. Black children had Medicaid health insurance coverage (67%) predominantly at the time of listing for HT. There was no significant overall difference in waitlist survival among the three groups supported with VAD at the time of listing (log-rank p = 0.4). On the other hand, the 90 day waitlist mortality after the VAD implantation at listing and while listed was the lowest among Black (6%) compared with White (13%) and Other (14%) ( p < 0.01). The multivariate regression analysis showed that Other race (hazard ratio [HR], 2.29; p < 0.01), Black race (HR, 2.13; p < 0.01), use of mechanical ventilation (HR, 1.72; p = 0.01), and Medicaid insurance (HR, 1.54; p = 0.04) were independently associated with increased 1 year posttransplant mortality. In conclusion, Black children had more access to durable VAD support than White children. The 90 day waitlist mortality was significantly lower in Black children compared with White and Other after VAD implantation. However, Black and Other racial/ethnic children with VAD at transplant had higher 1 year posttransplant mortality than White children. Future studies to elucidate the reasons for these disparities are needed., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2022.)

We aimed to study the disparity in the clinical profile and outcomes of hospitalized Multisystem Inflammatory Syndrome in Children (MIS-C) patients at our center. The second goal was to examine the temporal association with preceding SARS-CoV-2 infection by race/ethnicity in our community in Mississippi. We found the racial disparity in the prevalence of MIS-C exceeded its temporal association with SARS-CoV-2 infections. We included 51 consecutive MIS-C patients hospitalized, whose median age was 9 (interquartile range [IQR] 5-12) years, 58% were male, 71% were black, 25% were white, and 4% belonged to other groups. We found a delay between onset of symptoms and hospitalization in black patients compared with white patients with a median of 2 (IQR 0-7) vs median of 0 (0-5) urgent care visits ( P = .022), respectively. Black patients were hospitalized longer (median 8, IQR 2-39 days) than whites (median 5, IQR 3-14 days), P = .047. A total of 38.9% of blacks and 23.1% of whites were admitted to intensive care unit ( P = .498); 36.1% of blacks had severe cardiac involvement vs 23.1% of white patients, P = .531. Future studies of MIS-C are required to improve health equity for children.

The use of telehealth technology to connect with patients has expanded significantly over the past several years, particularly in response to the global coronavirus disease 2019 pandemic. This technical report describes the present state of telehealth and its current and potential applications. Telehealth has the potential to transform the way care is delivered to pediatric patients, expanding access to pediatric care across geographic distances, leveraging the pediatric workforce for care delivery, and improving disparities in access to care. However, implementation will require significant efforts to address the digital divide to ensure that telehealth does not inadvertently exacerbate inequities in care. The medical home model will continue to evolve to use telehealth to provide high-quality care for children, particularly for children and youth with special health care needs, in accordance with current and evolving quality standards. Research and metric development are critical for the development of evidence-based best practices and policies in these new models of care. Finally, as pediatric care transitions from traditional fee-for-service payment to alternative payment methods, telehealth offers unique opportunities to establish value-based population health models that are financed in a sustainable manner., Competing Interests: CONFLICT OF INTEREST DISCLOSURES: Dr Hackell is an expert reviewer and provides testimony to various law firms; the other authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2022 by the American Academy of Pediatrics.)

All children and adolescents deserve access to quality health care regardless of their race/ethnicity, health conditions, financial resources, or geographic location. Despite improvements over the past decades, severe disparities in the availability and access to high-quality health care for children and adolescents continue to exist throughout the United States. Economic and racial factors, geographic maldistribution of primary care pediatricians, and limited availability of pediatric medical subspecialists and pediatric surgical specialists all contribute to inequitable access to pediatric care. Robust, comprehensive telehealth coverage is critical to improving pediatric access and quality of care and services, particularly for under-resourced populations., Competing Interests: POTENTIAL CONFLICTS OF INTEREST: Dr Hackell is an expert reviewer and provides testimony to various law firms; the other authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2021 by the American Academy of Pediatrics.)

This is a cross-sectional study of 29 published cases of acute myopericarditis following COVID-19 mRNA vaccination. The most common presentation was chest pain within 1-5 days after the second dose of mRNA COVID-19 vaccination. All patients had an elevated troponin. Cardiac magnetic resonance imaging revealed late gadolinium enhancement consistent with myocarditis in 69% of cases. All patients recovered clinically rapidly within 1-3 weeks. Most patients were treated with non-steroidal anti-inflammatory drugs for symptomatic relief, and 4 received intravenous immune globulin and corticosteroids. We speculate a possible causal relationship between vaccine administration and myocarditis. The data from our analysis confirms that all myocarditis and pericarditis cases are mild and resolve within a few days to few weeks. The bottom line is that the risk of cardiac complications among children and adults due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection far exceeds the minimal and rare risks of vaccination-related transient myocardial or pericardial inflammation.

This review discusses the potential drug and device therapies for pediatric heart failure (HF) due to reduced systolic function. It is important to realize that most drugs that are used in pediatric HF are extrapolated from adult cardiology practices or consensus guidelines based on expert opinion rather than on evidence from controlled clinical trials. It is difficult to conclude whether the drugs that are well established in adult HF trials are also beneficial for children because of tremendous heterogeneity in the mechanism of HF in children and variations in the pharmacokinetics and pharmacodynamics of drugs from birth to adolescence. The lessons learned from adult trials can guide pediatric cardiologists to design clinical trials of the newer drugs that are in the pipeline to study their efficacy and safety in children with HF. This paper ' s focus is that the reader should specifically think through the pathophysiological mechanism of HF and the mode of action of drugs for the selection of appropriate pharmacotherapy. We review the drug and device trials in adults with HF to highlight the knowledge gap that exists in the pediatric HF population.

Objective: To update pediatric subspecialty workforce data to support evidence-based legislation and public policy decisions by replicating the American Academy of Pediatrics' 1998 Future of Pediatric Education (FOPE II) workforce survey., Methods: A descriptive and comparative analysis of survey responses from 9950 US pediatric subspecialists who completed an electronic survey., Results: Pediatric subspecialists are working fewer hours and spending less of their time in direct patient care than they did in 1998 but the mean hours worked differs significantly according to subspecialty. Most subspecialists continue to be board-certified, white, non-Hispanic men, although the percentage who are women and from minority groups has increased. The proportion of subspecialists practicing in an academic medical center has increased since 1998. Thirty percent of pediatric subspecialists reported appointment wait times of >2 weeks and pediatric subspecialists in developmental pediatrics, endocrinology, and neurology identified much longer wait times than other subspecialists., Conclusion: The demographic and practice characteristics of pediatric subspecialists have changed since the FOPE II survey and access to subspecialty care in a family's community remains a challenge. However, pediatric subspecialties are not monolithic and solutions to workforce shortages will need to take into account these differences to improve access to subspecialty care., (Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Background: Limited therapeutic options are available for Fontan patients with dysfunctional or failing single ventricle physiology. This study describes the evaluation of an alternative, non-invasive, at-home therapeutic compression treatment for Fontan patients. Our hypothesis is that routinely administered, externally applied compression treatments to the lower extremities will augment systemic venous return, improve ventricular preload, and thus enhance cardiac output in Fontan patients., Methods: To initially evaluate this hypothesis, we employed the NormaTec pneumatic compression device (PCD) in a pilot clinical study (n=2). This device is composed of inflatable trouser compartments that facilitate circumferentially and uniformly applied pressure to a patient's lower extremities. Following an initial health screening, test subjects were pre-evaluated with a modified-Bruce treadmill exercise stress test, and baseline data on cardiorespiratory health was collected. After training, test subjects conducted 6 days of external compression therapy at-home. Subjects were then re-evaluated with a final treadmill stress test and data acquisition of new cardiorespiratory parameters., Results: Both subjects demonstrated improvement in exercise duration time, peak oxygen volume, and ventilator threshold, as compared to the baseline evaluation., Conclusions: These findings are promising and provide the foundation for future studies that will focus on increasing study participation (sample size) to better assess the clinical benefit of compression therapy for Fontan patients., Competing Interests: Conflicts of Interest: Joseph Hernandez is now the Director of Research for the Frederick Banting Foundation. The other authors have no conflicts of interest to declare.

The use of mechanical circulatory support (MCS) devices is a viable therapeutic treatment option for patients with congestive heart failure. Ventricular assist devices, cavopulmonary assist devices, and total artificial heart pumps continue to gain acceptance as viable treatment strategies for both adults and pediatric patients as bridge-to-transplant, bridge-to-recovery, and longer-term circulatory support alternatives. We present a review of the current and future MCS devices for patients having congenital heart disease (CHD) with biventricular or univentricular circulations. Several devices that are specifically designed for patients with complex CHD are in the development pipeline undergoing rigorous animal testing as readiness experiments in preparation for future clinical trials. These advances in the development of new blood pumps for patients with CHD will address a significant unmet clinical need, as well as generally improve innovation of the current state of the art in MCS technology., (© 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

The use of telemedicine technologies by primary care pediatricians, pediatric medical subspecialists, and pediatric surgical specialists (henceforth referred to as "pediatric physicians") has the potential to transform the practice of pediatrics. The purpose of this policy statement is to describe the expected and potential impact that telemedicine will have on pediatric physicians' efforts to improve access and physician workforce shortages. The policy statement also describes how the American Academy of Pediatrics can advocate for its members and their patients to best use telemedicine technologies to improve access to care, provide more patient- and family-centered care, increase efficiencies in practice, enhance the quality of care, and address projected shortages in the clinical workforce. As the use of telemedicine increases, it is likely to impact health care access, quality, and education and costs of care. Telemedicine technologies, applied to the medical home and its collaborating providers, have the potential to improve current models of care by increasing communication among clinicians, resulting in more efficient, higher quality, and less expensive care. Such a model can serve as a platform for providing more continuous care, linking primary and specialty care to support management of the needs of complex patients. In addition, telemedicine technologies can be used to efficiently provide pediatric physicians working in remote locations with ongoing medical education, increasing their ability to care for more complex patients in their community, reducing the burdens of travel on patients and families, and supporting the medical home. On the other hand, telemedicine technologies used for episodic care by nonmedical home providers have the potential to disrupt continuity of care and to create redundancy and imprudent use of health care resources. Fragmentation should be avoided, and telemedicine, like all primary and specialty services, should be coordinated through the medical home., (Copyright © 2015 by the American Academy of Pediatrics.)

Mechanical assistance of the Fontan circulation is hypothesized to enhance ventricular preload and improve cardiac output; however, little is known about the fluid dynamics. This study is the first to investigate the three-dimensional flow conditions of a blood pump in an anatomic Fontan. Laser measurements were conducted having an axial flow impeller in the inferior vena cava. Experiments were performed for a physiologic cardiac output, pulmonary arterial flows, and pump speeds of 1000-4000 rpm. The impeller had a modest effect on the flow conditions entering the total cavopulmonary connection at low pump speeds, but a substantial impact on the velocity at higher speeds. The higher speeds of the pump disrupted the recirculation region in the center of the anastomosis, which could be advantageous for washout purposes. No retrograde velocities in the superior vena cava were measured. These findings indicate that mechanical assistance is a viable therapeutic option for patients having dysfunctional single ventricle physiology., (Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Single ventricle anomalies are a challenging set of congenital heart defects that require lifelong clinical management due to progressive decline of cardiovascular function. Few therapeutic devices are available for these patients, and conventional blood pumps are not designed for the unique anatomy of the single ventricle physiology. To address this unmet need, we are developing an axial flow blood pump with a protective cage or stent for Fontan patients. This study investigates the 3-D particle image velocimetry measurements of two cage designs being deployed in a patient-specific Fontan anatomy. We considered a control case without a pump, impeller placed in the inferior vena cava, and two cases where the impeller has two protective stents with unique geometric characteristics. The experiments were evaluated at a cardiac output of 3 L/min, a fixed vena caval flow split of 40%/60%, a fixed pulmonary arterial flow split of 50%/50%, and for operating speeds of 1000-4000 rpm. The introduction of the cardiovascular stents had a substantial impact on the flow conditions leaving the pump and entering the cavopulmonary circulation. The findings indicated that rotational speeds above 4000 rpm for this pump could result in irregular flows in this specific circulatory condition. Although retrograde flow into the superior vena cava was not measured, the risk of this occurrence increases with higher pump speeds. The against-with stent geometry outperformed the other configurations by generating higher pressures and more energetic flows. These results provide further support for the viability of mechanical cavopulmonary assistance as a therapeutic treatment strategy for Fontan patients., (Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Limited treatment options for patients having dysfunctional single ventricle physiology motivate the necessity for alternative therapeutic options. To address this unmet need, we are developing a collapsible axial flow blood pump. This study investigated the impact of geometric simplicity to facilitate percutaneous placement and maintain optimal performance. Three new pump designs were numerically evaluated. A transient simulation explored the impact of respiration on blood flow conditions over the entire respiratory cycle. Prototype testing of the top performing pump design was completed. The top performing Rec design generated the highest pressure rise range of 2-38 mm Hg for flow rates of 1-4 L/min at 4000-7000 RPM, exceeding the performance of the other two configurations by more than 26%. The blood damage indices for the new pump designs were determined to be below 0.5% and predicted hemolysis levels remained low at less than 7 × 10(-5)  g/100 L. Prototype testing of the Rec design confirmed numerical predictions to within an average of approximately 22%. These findings demonstrate that the pumps are reasonably versatile in operational ability, meet pressure-flow requirements to support Fontan patients, and are expected to have low levels of blood trauma., (Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

A mechanical blood pump specifically designed to increase pressure in the great veins would improve hemodynamic stability in adolescent and adult Fontan patients having dysfunctional cavopulmonary circulation. This study investigates the impact of axial-flow blood pumps on pressure, flow rate, and energy augmentation in the total cavopulmonary circulation (TCPC) using a patient-specific Fontan model. The experiments were conducted for three mechanical support configurations, which included an axial-flow impeller alone in the inferior vena cava (IVC) and an impeller with one of two different protective stent designs. All of the pump configurations led to an increase in pressure generation and flow in the Fontan circuit. The increase in IVC flow was found to augment pulmonary arterial flow, having only a small impact on the pressure and flow in the superior vena cava (SVC). Retrograde flow was neither observed nor measured from the TCPC junction into the SVC. All of the pump configurations enhanced the rate of power gain of the cavopulmonary circulation by adding energy and rotational force to the fluid flow. We measured an enhancement of forward flow into the TCPC junction, reduction in IVC pressure, and only minimally increased pulmonary arterial pressure under conditions of pump support., (Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Patients with Fontan palliation and single-ventricle physiology encounter multiple comorbidities including plastic bronchitis, a disease characterised by the plugging of small and large airways by rubbery, white casts. To date, no controlled clinical trials have demonstrated effective treatment of plastic bronchitis. We report the application of aerosolised heparin, which has published success in non-cardiac-related pulmonary disease, for this complication in a Fontan patient.

Background: This study investigated the application of circumferentially applied, external pressure to the lower extremities as a preventative measure and long-term clinical treatment strategy for Fontan patients., Objective: We hypothesized that the application of circumferential pressure to the lower limbs will augment venous return and thus cardiac output., Methods: Two patients (an extra-cardiac and intra-atrial Fontan) were evaluated. Both trials were conducted during a routine cardiac catheterization. The aortic and inferior vena cava (IVC) pressures were recorded. We applied three different external pressures to the lower limbs based on the patient's diastolic pressure. Each pressure was applied with a one-minute rapid inflate/deflate period for a total of five cycles and a rest period between pressure intervals., Results: Patient 1 (age 37, female) demonstrated pressure rises of 10-15 mmHg in both the aortic and IVC pressures. Patient 2 (age 24, male) had undetectable pressure rise during the first pressure cycles and notable pressures rise of approximately 8-12 mmHg during the third cycle., Conclusions: External pressure application redistributes blood volume or cardiac output as a result of impedance in the lower extremities, enhancing venous pressure and return. Our findings strongly suggest an acute benefit from the implementation of external mechanical compression of the lower vasculature to increase cardiac output in Fontan patients.

This numerical study examined the performance of an intravascular axial flow blood pump for mechanical hemodynamic support of patients in the setting of Fontan failure, which presently has few treatment options. Three anatomically accurate geometries of the total cavopulmonary connection (TCPC) were generated using patients' magnetic resonance imaging data. These patient-specific geometries, as well as an idealized version with cylindrical vessels, were computationally analyzed with and without a pump in the inferior vena cava. Pressure flow characteristics, energy gain calculations, and blood damage analyses were performed for each model. The pump produced pressures of 1-14 mm Hg for 1500-4000 revolutions per minute, flow rates of 1-4 L/min, and pulmonary artery pressures of 8-24 mm Hg. Comparison of pump performance among the four models showed minimal intermodel differences (<5% deviation) in the pressure rise generated by the pump, the IVC pressure, and the energy imparted to the system by the pump. Blood damage analysis showed maximum fluid scalar stress values of 372 Pa or less, and the blood damage index was less than 2% in all of the models. These results suggest that this axial flow blood pump performs consistently in a variety of TCPC vessel geometries with low risk of blood trauma., (© 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Objective: Advances in the geometric design of blood-contacting components are critically important as the use of minimally invasive, intravascular blood pumps becomes more pervasive in the treatment of adult and pediatric patients with congestive heart failure. The present study reports on the evaluation of uniquely shaped filaments and diffuser blades in the development of a protective stent for an intravascular cavopulmonary assist device for patients with a single ventricle., Methods: We performed numeric modeling, hydraulic testing of 11 stents with an axial flow blood pump, and blood bag experiments (n = 6) of the top-performing stent geometries to measure the levels of hemolysis. A direct comparison using statistical analyses, including regression analysis and analysis of variance, was completed., Results: The stent geometry with straight filaments and diffuser blades that extended to the vessel wall outperformed all other stent configurations. The pump with this particular stent was able to generate pressures of 2 to 32 mm Hg for flow rates of 0.5 to 4 L/min at 5000 to 7000 RPM. A comparison of the experimental performance data to the numeric predictions demonstrated an excellent agreement within 16%. The addition of diffuser blades to the stent reduced the flow vorticity at the pump outlet. The average and maximum normalized index of hemolysis level was 0.0056 g/100 L and 0.0064 g/100 L, respectively., Conclusions: The specialized design of the stents, which protect the vessel wall from the rotating components of the pump, proved to be advantageous by further augmenting the pressure generation of the pump, reducing the flow vorticity at the pump outlet, and enhancing flow control., (Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Thousands of mechanical blood pumps are currently providing circulatory support, and the incidence of their use continues to increase each year. As the use of blood pumps becomes more pervasive in the treatment of those patients with congestive heart failure, critical advances in design features to address known limitations and the integration of novel technologies become more imperative. To advance the current state-of-the-art in blood pump design, this study investigates the inclusion of pitch-adjusting blade features in intravascular blood pumps as a means to increase energy transfer; an approach not explored to date. A flexible impeller prototype was constructed with a configuration to allow for a variable range of twisted blade geometries of 60-250°. Hydraulic experiments using a blood analog fluid were conducted to characterize the pressure-flow performance for each of these twisted positions. The flexible, twisted impeller was able to produce 1-25 mmHg for 0.5-4 L/min at rotational speeds of 5,000-8,000 RPM. For a given twisted position, the pressure rise was found to decrease as a function of increasing flow rate, as expected. Generally, a steady increase in the pressure rise was observed as a function of higher twisted degrees for a constant rotational speed. Higher rotational speeds for a specific twisted impeller configuration resulted in a more substantial pressure generation. The findings of this study support the continued exploration of this unique design approach in the development of intravascular blood pumps.

This study investigated the performance of a magnetically levitated, intravascular axial flow blood pump for mechanical circulatory support of the thousands of Fontan patients in desperate need of a therapeutic alternative. Four models of the extracardiac, total cavopulmonary connection (TCPC) Fontan configuration were evaluated to formulate numerical predictions: an idealized TCPC, a patient-specific TCPC per magnetic resonance imaging data, and each of these two models having a blood pump in the inferior vena cava (IVC). A lumped parameter model of the Fontan physiology was used to specify boundary conditions. Pressure-flow characteristics, energy gain calculations, scalar stress levels, and blood damage estimations were executed for each model. Suction limitation experiments using the Sylgard elastomer tubing were also conducted. The pump produced pressures of 1-16 mm Hg for 2000-6000 rpm and flow rates of 0.5-4.5 L/min. The pump inlet or IVC pressure was found to decrease at higher rotational speeds. Maximum scalar stress estimations were 3 Pa for the nonpump models and 290 Pa for the pump-supported cases. The blood residence times for the pump-supported cases were shorter (0.9 s) as compared with the nonsupported configurations (2.5 s). However, the blood damage indices were higher (1.5%) for the anatomic model with pump support. The pump successfully augmented pressure in the TCPC junction and increased the hydraulic energy of the TCPC as a function of flow rate and rotational speed. The suction experiments revealed minimal deformation (<3%) at 9000 rpm. The findings of this study support the continued design and development of this blood pump., (© 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Background: Pediatric physicians regularly face the problem of uncertain procedural anticoagulation in children, especially in neonates. We sought to evaluate the safety, plasma concentration (pharmacokinetics, PK), pharmacodynamics (PD), and dosing guidelines of bivalirudin when used as a procedural anticoagulant in pediatric percutaneous intravascular procedures., Methods and Results: Pediatric subjects undergoing percutaneous intravascular procedures for congenital heart disease were enrolled and received the current weight-based dose used in percutaneous coronary interventions (0.75 mg/kg bolus, 1.75 mg/kg/hr infusion). Blood samples for PK/PD analyses were drawn, and safety was evaluated by monitoring bleeding and thrombosis events. A total of 110 patients (11 neonates, 33 infants, 32 young children, and 34 older children) were enrolled; 106 patients received the protocol dose. The PK/PD response of bivalirudin was predictable and behaved in a manner similar to that in adults. Weight-normalized bivalirudin clearance rates were more rapid in neonates and decreased with increasing age. Bivalirudin concentrations were slightly lower in neonates, with a trend to an increase with age. Activating clotting time response was consistent with adult studies and prolonged in all age groups, and there was reasonable correlation between activating clotting time and bivalirudin plasma concentrations across all age groups. There were few major bleeding (2 of 110, 1.8%) or thrombotic events (9 of 110, 8.2%) reported., Conclusions: PK/PD response of bivalirudin in the pediatric population is predictable and behaves in a manner similar to that in adults. Using adult dosing, bivalirudin safely provided the expected anticoagulant effect in the pediatric population undergoing intravascular procedures for congenital heart disease., (Copyright © 2010 Wiley-Liss, Inc.)

Currently available mechanical circulatory support systems are limited for adolescent and adult patients with a Fontan physiology. To address this growing need, we are developing a collapsible, percutaneously-inserted, axial flow blood pump to support the cavopulmonary circulation in Fontan patients. During the first phase of development, the design and experimental evaluation of an axial flow blood pump was performed. We completed numerical modeling of the pump using computational fluid dynamics analysis, hydraulic testing of a plastic pump prototype, and blood bag experiments (n=7) to measure the levels of hemolysis produced by the pump. Statistical analyses using regression were performed. The prototype with a 4-bladed impeller generated a pressure rise of 2-30 mmHg with a flow rate of 0.5-4 L/min for 3000-6000 RPM. A comparison of the experimental performance data to the numerical predictions demonstrated an excellent agreement with a maximum deviation being less than 6%. A linear increase in the plasma-free hemoglobin (pfHb) levels during the 6-h experiments was found, as desired. The maximum pfHb level was measured to be 21 mg/dL, and the average normalized index of hemolysis was determined to be 0.0097 g/100 L for all experiments. The hydraulic performance of the prototype and level of hemolysis are indicative of significant progress in the design of this blood pump. These results support the continued development of this intravascular pump as a bridge-to-transplant, bridge-to-recovery, bridge-to-hemodynamic stability, or bridge-to-surgical reconstruction for Fontan patients.

This study evaluated the performance of an intravascular, percutaneously-inserted, axial flow blood pump in an idealized total cavopulmonary connection (TCPC) model of a Fontan physiology. This blood pump, intended for placement in the inferior vena cava (IVC), is designed to augment pressure and blood flow from the IVC to the pulmonary circulation. Three different computational models were examined: (i) an idealized TCPC without a pump; (ii) an idealized TCPC with an impeller pump; and (iii) an idealized TCPC with an impeller and diffuser pump. Computational fluid dynamics analyses of these models were performed to assess the hydraulic performance of each model under varying physiologic conditions. Pressure-flow characteristics, fluid streamlines, energy augmentation calculations, and blood damage analyses were evaluated. Numerical predictions indicate that the pump with an impeller and diffuser blade set produces pressure generations of 1 to 16 mm Hg for rotational speeds of 2000 to 6000 rpm and flow rates of 1 to 4 L/min. In contrast, for the same flow range, the model with the impeller only in the IVC demonstrated pressure generations of 1 to 9 mm Hg at rotational speeds of 10,000 to 12,000 rpm. Influence of blood viscosity was found to be insignificant at low rotational speeds with minimal performance deviation at higher rotational speeds. Results from the blood damage index analyses indicate a low probability for damage with maximum damage index levels less than 1% and maximum fluid residence times below 0.6 s. The numerical predictions further indicated successful energy augmentation of the TCPC with a pump in the IVC. These results support the continued design and development of this cavopulmonary assist device., (© 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Fistulas between the airways and the digestive tract are a rare complication of esophagectomy. We describe such a fistula complicated by recurrent pneumonia. We successfully closed the fistula with an Amplatzer Septal Occluder (AGA Medical Corp, Plymouth, MN), a nitinol device designed for percutaneous closure of congenital heart defects. The device was deployed under direct visualization through rigid bronchoscopy., (2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to determine the prevalence of the metabolic syndrome at baseline and after 6 months of lifestyle modification among obese adolescents referred to a multidisciplinary weight management program., Methods: A total of 165 obese adolescents were evaluated at baseline, and measurements were repeated in 57 subjects who completed 6 months of the program. Metabolic syndrome was defined as having three or more of the following: a body mass index (BMI) >97(th) percentile, hypertension, low high-density lipoprotein cholesterol (HDL-C), hypertriglyceridemia, and impaired fasting glucose (IFG)., Results: The prevalence of a BMI >97(th) percentile, hypertension, hypertriglyceridemia, low HDL-C, and IFG was 92.7, 54.5, 29.1, 26.7, and 2.4%, respectively. The prevalence of the metabolic syndrome at baseline was 30.3%. After 6 months of lifestyle modification, BMI z scores, percent body fat, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) decreased significantly from baseline; however, there was no significant change in the number of subjects demonstrating >or=three criteria of the metabolic syndrome., Conclusions: Approximately one third of the study subjects met the criteria of the metabolic syndrome, emphasizing the growing concern for the future development of premature cardiovascular disease in this high-risk population. Our data suggest that new strategies for lifestyle modification may be needed to improve cardiovascular risk factors significantly among adolescents with obesity.

We report the first known case of a retro-aortic innominate vein providing continuity between both the left and right atria in the presence of a left superior vena cava and a normal coronary sinus. This unusual structure created a bidirectional shunt with clinical desaturation at baseline and it complicated the management of a 9-year-old patient while undergoing mechanical ventilation. An embryologic mechanism that explains the development of this complex remains elusive.

We report the first known closure of an aortic conduit with the Amplatzer plug device. The device was used in the case of a 20-year-old male who presented with an aortic conduit that had thrombosed and had formed a pseudo-aneurysm. A 14-mm plug and a 16-mm plug were used to close off the proximal portion of the conduit in preparation for surgery. The successful use of the device minimized the risk and the extent of the subsequent surgery.

Infants undergoing surgery for congenital heart disease are at risk for myocardial ischemia during cardiopulmonary bypass, circulatory arrest, or low-flow states. The purpose of this study was to demonstrate the effects of sildenafil, a selective phosphodiesterase-5 (PDE-5) inhibitor on myocardial functional improvement and infarct size reduction during ischemia/reperfusion injury in infant rabbits. Infant rabbits (aged 8 wk) were treated with sildenafil citrate (0.7 mg/kg i.v.) or normal saline 30 min before sustained ischemia for 30 min and reperfusion for 3 h. Transesophageal echocardiography (TEE) was used to assess left ventricular cardiac output (LVCO) and aortic velocity time integral (VTI). After ischemia/reperfusion, risk area was demarcated by Evan's blue dye and infarct size determined by computer morphometry of triphenyltetrazolium chloride-stained sections. The sildenafil-treated group had preservation and elevation in LVCO (143% of baseline, p < 0.05) and an elevated aortic VTI (145% of baseline, p < 0.05) after 30 min of ischemia compared with the control group LVCO (72% of baseline, p < 0.05) and aortic VTI (73% of baseline, p < 0.05). This is a statistically significant increase in LVCO and aortic VTI in the sildenafil group compared with controls (n = 6/group, p < 0.05). The sildenafil-treated group had significant reduction in infarct size (15.5 +/- 1.2 versus 33 +/- 2.3 in the saline group, % risk area, mean +/- SEM, n = 10-15/group, p < 0.05). For the first time, we have shown that sildenafil citrate promotes myocardial protection in infant rabbits as evidenced by postischemic preservation and elevation in LVCO and aortic VTI and reduction in infarct size.

The incidence of foramen ovale restriction or closure is greater in fetuses with congenital heart defects (CHDs) and obligate atrial shunting and/or left atrial hypertension. Foramen ovale restriction or closure in fetuses with CHD can cause distress in utero or at birth. We suggest performing serial ultrasound assessment for at-risk fetuses with CHD to best assure fetal well-being plan the timing and mode of delivery, and develop management protocols for in utero and postnatal care. The future for these patients may be more optimistic as fetal intervention procedures are developed and mastered.

Fetuses with complete heart block have an increased mortality with most deaths occurring in utero or during infancy. The cardiac evaluation of these fetuses is difficult since the ventricular rate is low and the heart is dilated. We have implemented a strategy that includes the biophysical profile, which assesses fetal well-being, in combination with the cardiovascular profile that assesses cardiac function and the circulation. We present two cases of fetal complete heart block in which early delivery was recommended due to worsening cardiovascular profile scores. Biophysical profile scores were normal. Both babies were successfully treated, despite having risk factors that predicted poor outcomes. We hypothesize that our management protocol initiated intervention before fetal compromise, hydrops, and myocardial damage occurred. We recommend an evaluation of heart function in addition to an assessment of fetal well-being in fetuses with complete heart block. Early delivery should be considered if there is evidence of distress and/or deteriorating cardiac function.

Background and Objectives: The prognosis for infants with pulmonary atresia and intact ventricular septum (PA/IVS) is poor and they present a major management challenge. Mechanical penetration of the atretic pulmonary valve is an applicable option for decompression of the right ventricle and optimization of left ventricular function. The utilization of laser energy for debulking and vaporization of the atretic valve tissue is a relevant approach due to the potential for controlled, precise mode of energy distribution., Study Design/patients and Methods: A 4-month-old female with PA/IVS whose failure to thrive was accompanied by critical hemodynamic abnormalities received successful percutaneous pulmonary valve plate ablation by a 0.9 mm pulsed-wave ultraviolet excimer laser catheter (308 nm wavelength, fluence 50 mJ/mm(2); 30 Hz). A "step-by-step" lasing technique was applied whereby the tip of the emitting laser catheter is advanced ahead of a guide wire that serves mainly as support for positioning of that catheter., Results: Adequate penetration of the atretic tissue enabled introduction of balloon dilations resulting in patency of the atretic valve, decompression of the right ventricle, improved right and left ventricular hemodynamics, and oxygenation. To further investigate the effect of excimer laser energy on atretic valvular tissue this laser was applied in a specimen of heart from an infant who died because of PA/IVS. Histopathologic examination of the irradiated tissue revealed no laser-induced injury to the pulmonary valve., Conclusions: Thus, laser ablation and penetration of an atretic pulmonary valve is feasible and safe. The penetration of the atretic valve with the laser catheter enables subsequent introduction of various sizes balloon dilations. The application of available laser sources for treatment of congenital heart diseases is reviewed., ((c) 2004 Wiley-Liss, Inc.)

A common brachiocephalic trunk is an anatomic variant in which both common carotid arteries and the right subclavian artery arise from the aortic arch via a single trunk. The impact of this condition on associated congenital cardiac malformations is presently unknown. Out of a total of 1480 cardiac catheterizations performed in children over a period of 10 years, we discovered 48 patients (3.2%) to have a common brachiocephalic trunk, of whom 98% had associated congenital cardiac malformations. A spectrum of associated lesions was identified, including left-to-right shunts in 19 patients, right-sided anomalies in 18 patients, left-sided obstructive lesions in 12 patients, and coronary arterial abnormalities in 10 patients, eight of whom had other cardiac defects. Genetic syndromes were present in one-fifth of the cases. When found with left-sided malformations, the common trunk was associated with persistent hypoplasia of the aortic arch, likely related to diminished flow through the arch during development. In each of four patients in whom the brachiocephalic trunk had been used during construction of a palliative shunt, we observed inadequate growth and deformation of the pulmonary arteries. Thus, angiographic identification of a common brachiocephalic trunk may be a marker for the presence of accompanying congenital cardiac defects and coronary arterial abnormalities. Understanding the pathophysiologic effects of the common trunk is important when planning the palliative or corrective procedures, and when assessing the potential benefit of the surgical repair over the long term.

Obstruction of the reconstructed aortic arch, or the neoaortic arch, is now known to be an important factor increasing mortality after the Norwood operation for hypoplastic left heart syndrome. Transcatheter balloon angioplasty has been shown to provide effective relief of both native aortic coarctation and obstructions of the aortic arch occurring subsequent to therapeutic intervention. We sought to determine the outcomes of balloon angioplasty used as an initial treatment for obstruction of the neoaortic arch occurring after the Norwood operation. We gathered the characteristics of 58 patients with such obstruction from 8 institutions, noting procedural factors and outcomes of initial balloon dilation. Obstruction occurred at a median interval of 4 months, with a range from 1.5 months to 6.3 years, after a Norwood operation. Ventricular dysfunction was present before dilation in 13 patients. Mean peak to peak systolic pressure gradients were acutely reduced from 31+/-20 mm Hg to 6+/-9 mmHg (p<0.001), with outcome subjectively judged to be successful in 89%. Three patients with pre-existing ventricular dysfunction died within 48 hours of dilation. There were 10 additional deaths during the period of follow-up, with Kaplan Meier estimates of survival after intervention of 87% at 1 month, 77% at 12 months, and 72% after 15 months. In addition, 9 patients required re-intervention during the period of follow-up, with Kaplan Meier estimates of freedom from re-intervention after dilation of 87% at 6 months, 78% at 12 months and 74% after 18 months. Although transcatheter dilation of neoaortic arch obstructions after Norwood operation is successful, there is a high risk of re-intervention and ongoing mortality in this subgroup of patients. Close follow-up is recommended.

Background: Graft coronary disease is a leading cause of death in patients who have undergone cardiac transplantation. The purpose of this study was to evaluate regional wall motion response and quantitative measures of ventricular function during dobutamine stress echocardiography (DSE) in pediatric transplantation patients., Methods: Eleven patients were evaluated the first year after transplantation (10/11 no rejection). Ten of the 11 were reevaluated 1.2 +/- 0.3 years later (9/10 no rejection)., Results: Dobutamine stress echocardiography revealed the following: (1) baseline regional wall motion abnormalities in 80% that resolved in all, (2) increased heart rate and blood pressure, (3) no change in left ventricular end-diastolic diameter, (4) decreased end-systolic diameter, (5) decreased wall stress and increased velocity of circumferential fiber shortening, (6) increased VCFcZ score (representing systolic left ventricular function), and (7) a decreased mitral passive-to-active filling ratio. Patients with rejection had abnormal VCFcZ scores at rest., Conclusions: Pediatric transplantation patients without rejection have baseline regional wall motion abnormalities. With DSE, the following are present: (1) resolution of wall motion abnormalities, (2) increased contractility independent of load, and (3) changes in diastolic parameters that reflect increased heart rate. Patients with rejection may have abnormal contractility at rest.

Background: Children with long-term exposure to passive cigarette smoke may be at elevated risk for the development of premature coronary artery disease (CAD)., Objective: To examine how CAD risk factors, exposure to passive smoking, sex, and race are related in pubertal children and to determine if there is an identifiable childhood risk profile (i.e., does passive smoking interact with other coronary risk factors to increase the risk of developing premature CAD)., Design: Cohort analytic study., Setting: The Medical College of Virginia (MCV) Twin Study, Richmond, Va., Subjects: Randomly selected twins from 408 11-year-old twin pairs recruited from nearby schools., Methods: Data collection occurred at 18-month intervals on family and health histories, smoking and alcohol consumption, blood pressure, anthropometrics, and biochemical assays. Data from cohorts of 11-year-olds studied through age 15 years were analyzed by repeated-measures analyses of variance using a mixed modeling approach. Models for high-density lipoprotein cholesterol (HDL-C) included race, sex, passive smoking status, weight, systolic and diastolic blood pressures, and all interactions., Results: Passive smoke exposure was greater in white families than in black families. Levels of HDL-C and HDL2-C (HDL subfraction 2 cholesterol) were lower in white children than in black children (visit 1: HDL-C, mean +/- SD, 1.21+/-0.26 vs. 1.31+/-0.26 mmol/L [47.0+/-10.1 vs. 50.6+/-10.1 mg/dL], P< or =.01; HDL2, mean +/- SD, 0.31+/-0.18 vs. 0.41+/-0.19 mmol/L [12.3+/-7.0 vs. 15.9+/-7.4 mg/dL], P< or =.001). Children with a family history of cardiovascular disease had differences in HDL-C levels related to race that were worsened by exposure to cigarette smoke. In these children, HDL-C level was lower in those exposed to passive smoking (visit 1: 1.18+/-0.23 vs. 1.25+/-0.23 mmol/L [45.6+/-9 vs. 48.2+/-9 mg/dL] and visit 4: 0.98+/-0.10 vs. 1.19+/-0.18 mmol/L [37.8+/-4 vs. 46.0+/-7 mg/dL]; P<.001), with white children having lower HDL-C levels than black children (visit 1: 1.12+/-0.21 vs. 1.36+/-0.23 mmol/L [43.2+/-8 vs. 52.7+/-9 mg/ dL] and visit 4: 0.97+/-0.31 vs. 1.01+/-0.31 mmol/L [37.6+/-12 vs. 39.0+/-12 mg/dL]; P = .004). In white families, as weight increased, boys exposed to passive smoking showed the greatest decrease in HDL-C level (P<.01 for weight by sex and passive smoking interaction). Risk factors for CAD, such as blood pressure, interacted with HDL-C and these relationships varied by race and sex., Conclusions: Pubertal children with long-term passive cigarette smoke exposure have lower HDL-C levels. Racial differences in HDL-C levels are related to passive smoke exposure. In children with a family history of cardiovascular disease, interactions exist between passive smoking, HDL-C level, and blood pressure that differ by sex and race. White males exposed to passive smoking who have a family history of cardiovascular disease and higher weights and diastolic blood pressures may be at special risk for premature CAD.

Surgical management of patent ductus arteriosus (PDA) in the elderly population is complicated by a fragile aortic wall due to atheromatous lesions, the presence of friable tissue at the surgical site, and calcification of the ductus. A viable option for the elderly patient is transcatheter closure of the PDA using a synthetic plug. Transcatheter coil occlusion has been shown to be an effective nonsurgical technique for closure of the persistently PDA in a younger population. We report a case of a 75 year old woman who had complete occlusion of her PDA with a single Gianturco coil after recurrence of her ductus 3 years post surgical ligation. The successful transcatheter treatment is presented with emphasis on the simple and safe technique utilized. (c)1999 by CVRR, Inc.

Percutaneous therapeutic embolization may be an effective strategy to manage distal coronary perforations or inadvertent iatrogenic coronary arteriovenous fistula complicating revascularization procedures. We present two cases in which embolization techniques were used to manage these patients and avoid the need for surgical intervention.

Balloon dilation (BD) is reported as an effective treatment for isolated discrete thin membranous subaortic stenosis (SAS). We asked if BD of SAS with associated cardiac defects: 1) is effective; 2) creates or worsens mitral insufficiency in the presence of valvar membrane attachment; and 3) creates or worsens aortic insufficiency. BD was performed on 13 patients (9 females, 4 males with a mean age of 5.8 years and an age range of 1-14 years old) for SAS with the following associated defects: VSD (6 patients), coarctation (4 patients), complete atrioventricular canal (1 patient), tetralogy of Fallot (1 patient), and abnormal mitral valve (4 patient). Prior intracardiac surgical procedures (3 for SAS resection) had been performed in 46% of the study group. Peak gradient was reduced from 53 +/- 40 mmHg to 31 +/- 25 mmHg (p < 0.01). The resulting gradient was related to the predilation gradient (r = 0.71; p =.006). Thin membranes (< 3 mm) were associated with lower initial gradient (p < 0.02), lower resulting gradient (p < 0.001) and a greater percent gradient reduction (76% versus 36%; p < 0.01). Aortic insufficiency, which was present predilation in 77%, did not change and was not created in any patient. Mitral valve membrane attachment was present in 69% and associated with a lower resulting gradient (p < 0.006). Mitral insufficiency was not created in 10 patients, was unchanged in 2 and was improved in 1 patient. Surgical procedures were ultimately required in 8 patients during follow-up. BD of SAS associated with other cardiac defects achieves the following: 1) reduces SAS gradient in selected patients without creating or worsening aortic insufficiency; 2) does not create or worsen mitral insufficiency when mitral valve membrane attachment is present; 3) improves preoperative hemodynamics; and 4) is unlikely to be effective in post-surgical recurrence.

Background: Both resting and exercise levels of blood pressure in individuals have been used as predictors of adult hypertension. One possible mechanism underlying the relation between childhood resting and exercise blood pressure and future blood pressure is a set of genes expressed in childhood that persists to regulate adult blood pressure., Methods and Results: To investigate the genetic relation of blood pressure and heart rate during both rest and exercise, we asked: (1) Are the genes that regulate resting hemodynamic variables the same genes that regulate these variables during exercise? (2) How much of the variance in exercise hemodynamic variables is genetic and how much is environmental? (3) Do the genetic and environmental influences on hemodynamic responses change with increasing levels of exercise? To determine how genetic and environmental effects expressed at rest influenced responses during dynamic exercise, a genetic analysis was conducted by fitting a series of models to the covariance matrices with the use of the LISREL VII program., Conclusions: We found that all the genetic effects expressed at the later stages of exercise can be explained by genetic effects expressed at rest and at the first stage of exercise. The environmental effects appear to be workload specific and include errors of measurement.

We investigated the relative contributions of genetic, individual environmental, and shared environmental effects on 2,3-diphosphoglycerate (DPG) regulation in preadolescent children. In a population of 165 early pubescent boy and girl twin pairs (11.4 y old), of whom 63 were passive smokers, we asked: 1) Are there differences in the control of DPG levels between early pubertal boys and girls? 2) If present, are these differences influenced by exposure to passive cigarette smoke? Non-passive-smoking boys and girls had similar DPG levels. With exposure to passive smoke, DPG levels increased in boys (p = 0.02) but not in girls. Analysis of variance on DPG demonstrated a parental smoking effect (p = 0.008) and suggested an interactive effect between parental smoking and sex of the child (p = 0.08). Univariate genetic analyses suggested that genes operated at different magnitudes in boys (9%) and girls (39%) in explaining a significant portion of the variance in DPG. The magnitude of shared environmental influences was greater in boys (62%) than in girls (34%), whereas individual environmental effects were similar in boys (29%) and girls (26%). Early pubertal boys differ from girls in their regulation of DPG. Environmental stressors such as passive cigarette smoke may elicit different responses in males and females, even at an early age. The use of path analysis may provide important insights into the mechanisms and interactions of genetic and environmental effects that underly the childhood antecedents of atherosclerotic heart disease.

Background: In subjects of all ages, those who weigh the most often have the highest blood pressure. Thus, in epidemiological studies, weight is the most important correlate of blood pressure. Using the data from the Medical College of Virginia Twin Study, we asked these questions: 1) Do the same genetic paths that regulate body size also regulate systolic and diastolic blood pressure? 2) Are there distinct genetic pathways that regulate each of these variables? 3) Does environment play a major regulatory role? 4) Are the correlations among these variables mainly due to genetic or environmental effects? 5) Do genetic paths that regulate body size mediate the correlation between systolic blood pressure and diastolic blood pressure?, Methods and Results: We ascertained 253 Caucasian twin pairs living in the Commonwealth of Virginia. The average age was 11.2 +/- 0.2 years. We used multivariate path analyses to investigate the genetic relations among systolic blood pressure, diastolic blood pressure, and body size. We found that there was a highly significant genetic relation between systolic blood pressure and body size and between systolic and diastolic blood pressure. There are genetic paths that are shared within these two sets of variables, but in each case, the paths for each pair appear to be separate from one another., Conclusions: These analyses provide a method to partition correlation coefficients found in epidemiological studies into genetic and environmental components. The correlations found among these three variables are in large part due to these genetic relations. We found no genetic relation between diastolic blood pressure and body size.

Background: Left ventricular (LV) hypertrophy is a predictor of cardiovascular events in adults and has been observed in children and adolescents with hypertension. We wanted to establish the determinants of LV mass in normotensive preadolescent children. Our objectives were 1) to produce a simplified and generalizable model of the clinical variables that determine normal cardiac growth during childhood and 2) to understand better why males have an increased LV mass relative to females, even as children., Methods and Results: In a group of 243 eleven-year-old children, we analyzed anthropometric, hemodynamic, and echocardiographic data to define which variables were predictors of echocardiographically determined LV mass. Stepwise regression was used to predict LV mass overall, by sex, and by body size (body mass index). Overall, LV mass was directly related to weight, male sex, and systolic and diastolic blood pressure and inversely related to resting heart rate and skin-fold thicknesses. Systolic blood pressure was a determinant in boys but not in girls. Heart rate was a weak inverse correlate in both sexes. When the data were analyzed by body mass index quartile, weight was the sole predictor of LV mass in the largest children., Conclusions: We conclude that in normotensive preadolescent children, 1) weight, but not pondersity, is a strong predictor of LV mass; 2) body fat is negatively associated with LV mass; 3) boys have an increased LV mass relative to girls; and 4) boys and girls have similar anthropometric determinants and may have different hemodynamic determinants. Our data suggest that body size, and in particular lean body mass, explains much of the variability in cardiac growth seen in children. The influence of hemodynamic variables seems to be more limited. Our findings are of general interest because, although hypertensive heart disease is well described, the early developmental stages are not well understood.

Umbilical arterial and venous catheters, endotracheal tubes, and nasogastric tubes are routinely used in treating premature infants, and radiologists play a critical role in evaluating proper catheter and tube placement and recognizing potential complications. Ideally, an umbilical venous catheter should be positioned in the right atrium; an umbilical arterial catheter, between T-6 and T-10 (high position) or between L-3 and L-5 (low position); an endotracheal tube, 1.5 cm above the carina, with the infant's head in a neutral position; and a nasogastric tube, in the body of the stomach. Catheters and tubes can be malpositioned in a variety of vessels and the main stem bronchi, respectively. Complications include extraluminal placement of catheters (which can result in death), thrombi in the aorta and pulmonary artery, aortic aneurysm, subglottic stenosis, intubation granuloma, and perforation of the esophagus and stomach.

The conduction system was studied by serial section in three patients with intractable supraventricular tachycardias originating from the atrioventricular (AV) junction who died suddenly. The three patients were a 6 month old girl (Case 1), a 5 month old boy (Case 2) and a 22 year old woman (Case 3). The latter had a pacemaker inserted after surgical ablation of the AV node. The heart was hypertrophied and enlarged in all. In Case 1, the AV node was partly within the central fibrous body and there was a left-sided AV bundle with acute necrosis in the summit of the ventricular septum, adjacent to the AV node and bundle. In Case 2, the coronary sinus was displaced cranially close to the central fibrous body, resulting in abnormality of the latter, with entrapment, distortion and division of the AV node and bundle into two distinct components within the central fibrous body. In Case 3, a left-sided AV node was connected to the atrial septum. The right AV node was completely interrupted by sutures and the penetrating and branching bundle and bundle branches were markedly fibrosed. In addition, the atrial septum and summit of the ventricular septum showed marked inflammatory reaction with fibrosis, which was more marked on the right ventricular side. Histologic examination of the conduction system in all three cases demonstrated congenital abnormalities of the AV junction that may be related to the tachycardia. These findings emphasize the need to carefully evaluate the atrial septum and AV junctional area, including the coronary sinus, before ablative procedures are undertaken.(ABSTRACT TRUNCATED AT 250 WORDS)