A prospective evaluation of nesiritide in the treatment of pediatric heart failure.

This study sought to determine the potential of recombinant B-type natriuretic peptide (nesiritide) for the treatment of pediatric decompensated heart failure. Nesiritide is a widely used and effective treatment for decompensated heart failure (HF) in adults, but its safety and efficacy in pediatric patients is unclear. Outcomes of 55 separate nesiritide infusions of varying durations in 32 patients (13 males and 19 females; mean age, 8.01 years; range, 0.01-20.4) were evaluated prospectively. All patients received nesiritide in the intensive care unit. The starting dose (0.01 microg/kg/min) was titrated to a maximum of 0.03 microg/kg/min. All patients were monitored for clinical signs and symptoms, hemodynamics, urine output, electrolytes, oxygen requirements, and oral intake. Functional status was assessed by patients and/or their parents. All patients successfully underwent initiation and titration of nesiritide infusion. No hypotension or arrhythmias were noted during 478 cumulative days of therapy. Nesiritide was given safely with vasoactive medications. Mean urine output improved from 2.35 +/- 1.71 cc/kg/hr on the day before nesiritide initiation (baseline) to 3.10 +/- 1.94 cc/kg/hr on day 4 of treatment (p < 0.01). Serum creatinine decreased from 1.04 to 0.92 mg/dl (p = 0.096), mean central venous pressure from 13 to 7 mmHg (p = 0.018), and mean weight from 30.4 to 29.7 kg (p < 0.001) with therapy. Thirst, as subjectively assessed by patients old enough to respond, decreased with infusion in 31 of 42 cases (74%). Mean New York Heart Association functional class improved significantly (p < 0.001). Nesiritide infusion, alone or in combination, is a safe treatment for decompensated HF in pediatric patients. It is associated with decreased thirst and improved urine output and functional status, and it may be efficacious in the treatment of pediatric HF.

Design and implementation of the North American Pediatric Cardiomyopathy Registry.

The Pediatric Cardiomyopathy Registry (PCMR) was established to describe the epidemiologic features and clinical course of selected cardiomyopathies in patients aged 18 years or younger and to promote the development of etiology-specific treatments. Sixty-one private and institutional pediatric cardiomyopathy practices in the United States and Canada were recruited to participate in the PCMR. The registry consists of a prospective, population-based cohort of patients in 2 regions (New England and the Central Southwestern United States) and a retrospective cohort of patients diagnosed between 1991 and 1996. Annual follow-up data are collected on all patients. As of June 1999, the PCMR consisted of 337 prospectively identified and 990 retrospectively identified patients. The PCMR has demonstrated the feasibility of establishing a large database of sociodemographic and clinical information on children with pediatric cardiomyopathy. Through this cooperative effort, the PCMR will obtain precise estimates of the incidence of pediatric cardiomyopathy and a better understanding of the natural history of this disease.

The embryology of congenital heart defects.

The embryological development of the heart is an awesome and complex process. The heart is formed from groups of cells that coalesce into sheets of tissue. These sheets fuse to form a tube that grows into the atria and ventricles. The twists and turns of the developing heart tissue and the simultaneous septation of atria, ventricles, and truncus, along with a shifting of the atrioventricular canal and conus then position the portions of the heart in alignment to allow normal blood flow. Errors at any stage of embryological formation can result in specific congenital defects. Understanding the development of the heart in utero can provide the pediatric nurse a basis for understanding the physiological effects of embryological failures that result in congenital heart defects in the infant and child.

Epidemiology of anthracycline cardiotoxicity in children and adults.

Anthracyclines, potent cytotoxic agents used to treat a broad spectrum of malignancies, are limited in their use by an attendant risk of cardiotoxicity. Malignancies affect all age ranges, and anthracyclines are used in all age ranges, thereby exposing a broad population of patients to the development of heart disease. For some treated patients, anthracyclines affect cardiac muscle, resulting in cardiomyopathy. The type and degree of cardiomyopathy, as well as when during or after treatment the condition occurs, are dependent on what risk factors are present. Age is a major risk factor. Children and adults may develop restrictive and dilated cardiomyopathy. The length of subsequent survival and amount of subsequent somatic growth may influence late anthracycline-associated cardiac outcome. Early cardiotoxicity, occurring during or within 1 year of completion of treatment, is the largest risk factor for the development of late cardiotoxicity, which occurs beyond a year of completion of treatment. Risk factors, which appear to be specific for early cardiotoxicity in children, include black race, trisomy 21, and the use of amsacrine therapy after anthracycline therapy. More cardiotoxic effects are seen in survivors of childhood cancer, the longer from completion of treatment a patient is followed. Cumulative as well as peak anthracycline doses affect adults and children alike, and cardiotoxicity occurs early and late. In adults, left ventricular contractility is affected by anthracyclines. Children may manifest impairment of left ventricular contractility and increased afterload due to thinning of left ventricular walls. Patients with an early presentation of depressed left ventricular contractility are likely to show progression of cardiac disease with time. In addition, female gender appears to affect early and late cardiotoxicity in both adults and children, although this risk factor has been described predominantly in the survivors of childhood cancer. Thus, although anthracycline chemotherapy has improved overall survivorship of patients with cancer, there is a significant risk of cardiotoxicity associated with this class of drugs.