The use of phentolamine in the prevention of dopamine-induced tissue extravasation.

PURPOSE: The purpose of this study was to determine whether dopamine-induced tissue extravasation injury could be prevented with phentolamine. MATERIALS AND METHODS: This was a prospective, randomized, blinded, and controlled animal study. Forty rats were evaluated to document the effects of dopamine compared with normal saline on tissue integrity, whether any tissue damage was concentration or volume dependent, and to determine the minimum concentration of dopamine resulting in tissue injury. Dopamine concentrations of 0.8 mg/mL and 3.2 mg/mL were tested. In a second part of this study, an additional 40 rats were evaluated to assess the efficacy of two different doses of phentolamine (0.5 mg and 1 mg) or normal saline, when injected within 10 minutes of dopamine administration to prevent or reverse tissue extravasation. Extravasation sites were evaluated clinically and histologically at 2, 4, 6, and 8 hours and were compared with a baseline sample. Outcome measures were as follows: (1) prebiopsy was ectodermal erythema, induration, and blanching; (2) postbiopsy was bubbling, darkening, pallor, and hematoma of the muscle fascia. Histology included neutrophil migration, mast cell degranulation, edema, and hemorrhage. Fisher's Exact Test with the Bonferroni method were used for statistical analysis. RESULTS: Dopamine-induced extravasation resulted in tissue injury characterized by blanching and hematoma. Damage did not appear to be volume dependent, but may be related to the duration of infiltration. Subcutaneous injection with either dose of phentolamine appeared to be clinically effective in preventing tissue injury. However, microscopic evaluation of tissue samples was inconclusive. CONCLUSION: This study clinically supported the use of phentolamine for the prevention of dopamine-induced extravasation injury.

Unique association of a rapidly growing right atrial myxoma in a child with double-outlet right ventricle.

We describe a patient with double-outlet right ventricle in whom a large right atrial myxoma developed over approximately 6 months. This patient represents the first case described of a right atrial myxoma occurring in an unoperated patient with congenital heart disease other than an isolated atrial septal defect. Because the child was followed with serial echocardiograms, we can document the rapid growth of the tumor.

Transcatheter closure of the patient ductus arteriosus in adults using the Gianturco coil.

BACKGROUND AND HYPOTHESIS: Although results of surgical ligation of the patent ductus arteriosus (PDA) in the pediatric age group are excellent, surgical management of the adult with a PDA may be more problematic. The PDA that presents in adulthood may be calcified and friable, rendering simple ligation via a thoracotomy difficult, inadequate, and hazardous. Patch closure of the ductus arteriosus from either the aortic or pulmonary artery orifice using cardiopulmonary bypass or transient aortic cross-clamping is necessary but increases surgical risk. Furthermore, older patients with diseases unrelated to their PDA and patients with Down's syndrome may have higher risks with intubation, general anesthesia, and surgery. Early results of percutaneous transcatheter occlusion of the PDA with Gianturco coils performed under sedation and local anesthesia are promising. METHODS: Six adults with mean age of 39.1 years (range 23.1-62.0 years) were found to have an isolated PDA with mean minimum diameter of 2.7 mm (range 1.0-5.0 mm) at cardiac catheterization. All underwent percutaneous transcatheter occlusion of the PDA using Gianturco coils. RESULTS: Coil implantation was successful in all patients. There were no complications and all were discharged home within 24 hours. Complete ductal occlusion was seen immediately in 4 of 6 patients (67%) while 2 of 6 (33%) had small residual leaks. However, complete occlusion was achieved in all patients by 6 months following the procedure. CONCLUSION: Transcatheter occlusion of the PDA using coils is safe and efficacious in adults.

Additional aortopulmonary collaterals in patients referred for coil occlusion of a patent ductus arteriosus.

Coexisting aortopulmonary collaterals in patients diagnosed with a patent ductus arteriosus (PDA) are rare findings. Percutaneous transcatheter closure of PDA and requisite aortography offer an unique opportunity to identify and treat these systemic arterial anomailes, which would be missed by echocardiographic evaluation alone. The significance of these collaterals is unclear, but it may contribute to left heart dilation from additional left to right shunting in patients with an otherwise isolated small PDA. Of 18 patients undergoing transcatheter occlusion of a PDA with Gianturco coils, 2 were found to an additional significant aortopulmonary collaterals, which were also occluded.

Arterial stents in the management of neurofibromatosis and renovascular hypertension in a pediatric patient: case report of a new treatment modality.

A 17-year-old male with neurofibromatosis presented with severe hypertension secondary to an abdominal aortic coarctation and bilateral renal artery stenoses. Despite previous surgical bypass grafts and aggressive medical management, including treatment with diuretics, beta-blocker, calcium channel blocker, angiotensin converting enzyme (ACE) inhibitors, and direct vasodilator agents, severe hypertension persisted. Following intravascular stent placement in the aorta and both renal arteries, blood pressures normalized.

Percutaneous transcatheter coil occlusion of the patent ductus arteriosus aided by the nitinol snare: further observations.

PURPOSE: To assess the safety and efficacy of the nitinol snare to aid in the delivery of a Gianturco coil in percutaneous occlusion of a patent ductus arteriosus (PDA). METHODS: Seventeen patients (mean age 8.2 years) underwent catheterization and coil occlusion of a PDA (mean minimum diameter 1.9 mm). A nitinol snare was used to deliver and position the coil in the ductus. RESULTS: A single Gianturco coil was placed successfully in all patients, resulting in complete ductal occlusion documented by aortic angiography. Color echocardiography documented a trivial residual shunt in one patient who had no audible cardiac murmurs following the procedure. There was no hemodynamic or echocardiographic evidence of left pulmonary artery obstruction. There were no complications and all patients were discharged within 24 hr following the procedure. CONCLUSIONS: Percutaneous coil occlusion of the PDA is safe and effective. Snare-controlled coil delivery eliminates the risk of coil dislodgement and optimizes coil position.

Effect of blood pressure cuffs on neonatal circulation: their potential application to newborns with persistent pulmonary hypertension.

The contribution of vasoactive pharmacologic agents to the care of the infant with primary pulmonary hypertension of the newborn (PPHN) is hampered by their limited ability to act selectively on different vascular beds. In contrast, blood pressure (BP) cuffs decrease flow and increase resistance only in the extremities around which they are applied. They therefore offer a means of increasing systemic vascular resistance without affecting pulmonary vascular resistance, a hemodynamic effect that may be particularly desirable among PPHN patients receiving vasodilators. We studied the effect of BP cuffs on the circulation of nine healthy neonates and three infants with severe PPHN. Among the healthy neonates, inflation of the cuffs to 20 mmHg had no discernible hemodynamic effect. Inflation to systolic pressures, however, caused the left ventricular preejection period to increase from 36 +/- 9 ms to 45 +/- 10 ms, the end-diastolic dimension to increase from 1.80 +/- 0.16 cm to 1.92 +/- 0.16 cm, and the cardiac output to fall to 87 +/- 12% of baseline (all p < 0.05)--changes indicative of an increase in systemic vascular resistance. Application of BP cuffs to the patients with PPHN was associated with 10-25 mmHg increases in transcutaneous arterial oxygen tensions. Administration of tolazoline to these patients while the cuffs were inflated resulted in additional 10-20 mmHg increases and did not precipitate hypotension. These observations suggest that BP cuffs can play a useful role in the management of patients with PPHN.

Pediatric intrathoracic large airway obstruction: diagnostic and therapeutic considerations.

We describe seven patients who had intrathoracic airway obstruction resulting in severe respiratory distress. The patients were a four month old with bronchial cartilage hypoplasia presenting as congenital lobar emphysema; a one month old with segmental bronchomalacia; a one month old with tracheal bronchus; a two day old and a seven month old with aneurysmal distension of the pulmonary arteries secondary to tetralogy of Fallot, with absent pulmonary valve and atrioventricular canal with pulmonary poststenotic dilatation, respectively; a three year old with double aortic arch forming a vascular ring; and a three month old with tracheomalacia from tracheoesophageal fistula. The patients had various associated congenital defects, and all of them required one or more surgical procedures to repair the defects and relieve the airway obstruction. Five patients received endotracheal intubation with mechanical ventilation on their first admission, and three of them died postoperatively. The diagnostic workup to delineate the anatomic factors causing the obstruction, as well as to determine the therapeutic medical and surgical strategies to relieve it, are described. We conclude that the course of illness in most pediatric patients with intrathoracic airway obstruction is complex, is associated with high morbidity and mortality, and entails extensive multidisciplinary diagnostic and therapeutic efforts.

Guidelines for long-term management of patients with Kawasaki disease. Report from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association.

Long-term management of patients with Kawasaki disease should be tailored to the degree of coronary arterial involvement. This committee has made recommendations for each risk level about antiplatelet and anticoagulant therapy, physical activity, follow-up assessment by a pediatric cardiologist or primary care physician, and the appropriate diagnostic procedures that may be performed to evaluate cardiac disease. The risk level for a given patient with coronary arterial involvement may change over time because of changes in coronary artery morphology. The recommendations for management presented here are intended as practical interim guidelines until additional prospective or retrospective data are compiled to define more clearly the natural history of Kawasaki disease.

Cardiac size and function during adrenocorticotropic hormone-induced systolic systemic hypertension in infants.

The effects of adrenocorticotropic hormone (ACTH) on systolic blood pressure, and echocardiographic indexes of heart size and function were investigated in 14 infants. After 25 days (range 13 to 46) of treatment with ACTH, systolic blood pressure increased from 93 +/- 9 to 118 +/- 20 mm Hg (p < 0.001; mean +/- 1 SD). Systolic hypertension (systolic blood pressure greater than the 95th percentile for age) developed in 10 of 14 infants and was associated with an increase in left ventricular (LV) shortening fraction from 41 +/- 5% to 52 +/- 8% (p < 0.001). Myocardial hypertrophy and an increase in echocardiographic indexes of myocardial contractility were observed also. To assess the temporal relation between the onset of systolic hypertension and these cardiac changes, data from 8 infants with serial echocardiograms and blood pressure determinations were examined. After a mean 14 days (range 8 to 18) of ACTH, LV shortening fraction increased from 39 +/- 6% to 53 +/- 8% (p < 0.01), whereas systolic blood pressure remained normal in 7 of 8 infants. In addition, a decrease in LV end-systolic dimension was observed during this early phase. This report documents myocardial changes in individual patients, which occur before and during the development of systolic hypertension.

Acute myocardial infarction complicating prothrombin complex concentrate therapy in an 8-year-old boy with hemophilia A and factor VIII inhibitor.

PURPOSE: An 8-year-old boy with mild hemophilia A and inhibitors developed an acute myocardial infarction during treatment with prothrombin complex concentrates. CONCLUSIONS: This rare complication warrants restriction of dosage and length of treatment with these products to the recommended guidelines. It also appears that noninvasive cardiac monitoring of these patients is beneficial.

Second natural history study of congenital heart defects. Aortic stenosis: echocardiography.

BACKGROUND: Recent advances in the field of echocardiography have made it possible to obtain a complete morphological and hemodynamic assessment of patients with aortic stenosis. Therefore, comprehensive two-dimensional and Doppler examinations were performed on patients with aortic stenosis returning for the Second Natural History Study of Congenital Heart Defects (NHS-2). METHODS AND RESULTS: Two hundred thirty-two patients with aortic stenosis underwent comprehensive two-dimensional and Doppler examinations. Of these, 96 were in the medically treated group, 49 had undergone aortic valve replacement, and 87 had had aortic valvotomy. The valve replacement group had a significantly smaller left ventricular diastolic cavity than did the medically treated group; both had smaller dimensions than the valvotomy group. There was no significant difference in left ventricular wall thickness or fractional shortening among the three groups. The valvotomy group had a significantly higher mean aortic valve gradient than did either the medically treated group or the valve replacement group. The degree of aortic regurgitation was more severe in the valvotomy group than in the other two groups. For all patients, there was a direct relation between the aortic valve gradient and the mean wall thickness and an inverse relation between the aortic valve mean gradient and fractional shortening. The only echocardiographic parameter that correlated with the presence or absence of symptomatology was the fractional shortening. CONCLUSIONS: These observations provide an objective measurement for assessing the status of the aortic valve and left ventricular response in patients with aortic stenosis returning for NHS-2. Limitations of echocardiography in this study are discussed.

Second natural history study of congenital heart defects. Pulmonary stenosis: echocardiography.

BACKGROUND: Two-dimensional and Doppler echocardiography can provide information about valve morphology, right ventricular size and function, and hemodynamics in patients with pulmonary stenosis. Therefore, two-dimensional and Doppler echocardiographic examinations were performed on patients with pulmonary stenosis returning for the Second Natural History Study of Congenital Heart Defects. METHODS AND RESULTS: Three hundred twenty-five patients with pulmonary stenosis underwent two-dimensional and Doppler echocardiographic examinations. Of these, 115 were in the medically treated group, and 210 had undergone a previous operation. Patients in the valvotomy group had a higher incidence of right ventricular dysfunction and a larger right ventricular diastolic dimension. The valvotomy group had a lower pulmonary valve mean gradient and a lower right ventricular systolic pressure than the medically treated group. For all patients, there was no significant correlation of the echocardiographic variables with the presence or absence of symptoms, reflecting the low incidence of patients with cardiac decompensation. CONCLUSIONS: These observations provide an objective measurement for assessing the status of the pulmonary valve and right ventricular response in patients with pulmonary stenosis. Limitations of echocardiography in this study are discussed.

Second natural history study of congenital heart defects. Ventricular septal defect: echocardiography.

BACKGROUND: Two-dimensional and Doppler echocardiography can provide structural and hemodynamic information for patients with ventricular septal defects (VSDs). Therefore, two-dimensional and Doppler echocardiographic examinations were performed on patients with VSDs returning for the Second Natural History Study of Congenital Heart Defects. METHODS AND RESULTS: Five hundred fifty-six patients with VSDs underwent two-dimensional and Doppler echocardiographic examinations. Three hundred twenty-four patients were in the medically treated group, and 232 had undergone a previous operation. The location of the VSD was classified in 235 patients. Several Doppler measurements were used to calculate pulmonary artery pressures: tricuspid regurgitation peak systolic velocity, peak systolic velocity of VSD jet, pulmonary regurgitation end-diastolic velocity, and pulmonary artery acceleration time. The two methods that were found to be reliable consisted of the tricuspid regurgitation peak systolic velocity and the pulmonary regurgitation end-diastolic velocity. These measurements were obtained in only 26% of patients at all centers. At one center in which adult and pediatric echocardiography was performed in a single laboratory, these values were obtained in 60% of patients. CONCLUSIONS: Two-dimensional and Doppler echocardiography has the ability to provide a noninvasive method of assessing morphology and hemodynamics in patients with VSDs. However, the reliability and accuracy of hemodynamic measurements are dependent on operator experience.