Sudden infant death syndrome: a review for primary care physicians.
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Attitude to Death↗
Biomedical subjects
R E Shaddy
Publications and source records attributed to R E Shaddy.
Sinus node dysfunction in tuberous sclerosis.
Tuberous sclerosis is an autosomal dominant disease with potential for involvement of the skin, brain, lungs, kidneys, and heart. A case of prolonged sinus node pause and episodes of unresponsiveness in a 21-week-old infant with tuberous sclerosis is described. The infant subsequently underwent placement of an epicardial pacemaker. This case illustrates the importance of electrocardiographic studies in infants with tuberous sclerosis and seizure-like episodes.
Cardiac Pacing, Artificial↗
B-type natriuretic peptide levels in congenital heart disease.
The objective of this study was to evaluate the potential role of B-type natriuretic peptide (BNP) levels in children with congenital heart disease undergoing cardiac catheterization. Measurement of plasma BNP concentration has been shown to be useful in the diagnosis, risk stratification, and management of adult patients with congestive heart failure, but little is known about the role of BNP in children with structural congenital heart disease. We measured plasma BNP levels using the Triage BNP test in patients with congenital heart disease referred for diagnostic or interventional cardiac catheterization. Plasma BNP concentration was measured in 96 children and 11 adults > or = 19 years old (7.9+/-8.3 years) undergoing heart catheterization for underlying congenital heart disease. BNP levels ranged from < 5 to > 1300 pg/ml, with a median BNP concentration of 19.0 pg/ml. Baseline BNP concentrations were > 100.0 pg/ml on 19 occasions in 17 patients. The pressure difference between the left ventricle and ascending aorta was 10-110 mmHg in 21 patients. BNP concentrations for this cohort ranged from < 5.0 to 1060.0 pg/ml and correlated with the degree of left ventricular outflow obstruction (correlation coefficient, 0.661; p = 0.001). This study suggests that with additional research, BNP concentration may prove to be a useful clinical tool in managing children and adults with congenital heart disease.
Adolescent↗
An unusual variant of total anomalous pulmonary venous connection with varices and multiple drainage sites.
Total anomalous pulmonary venous connection (TAPVC) is an uncommon cardiac anomaly that has also rarely been associated with esophageal atresia. We report an unusual case of esophageal atresia with TAPVC with several varices and multiple drainage sites into the superior vena cava and portal vein.
Coronary Angiography↗
Evidence for early vessel involvement in the dysfunctional myocardium of Takayasu's arteritis.
A 15-year-old girl presented with persistent fevers, night sweats, leukocytosis, an elevated erythrocyte sedimentation rate, and a 13-pound weight loss over 2 months. Duplex Doppler scans, computed tomographic scan, and magnetic resonance imaging studies were suggestive of Takayasu's arteritis. Left ventricular dysfunction occurred during the episode of active disease, and an endomyocardial biopsy demonstrated increased HLA-DR (human leukocyte antigen-DR) on the endothelium and evidence of immune complex deposition in the walls of small vessels. One year later, after treatment with corticosteroids and resolution of clinical symptoms, repeat endomyocardial biopsy revealed focal interstitial fibrosis and persistent immune complex deposition. These results indicate that the inflammatory, vasculitic process affecting the large vessels in Takayasu's arteritis may also involve the endomyocardium and its small vessels resulting in ventricular dysfunction.
Adolescent↗
Reversal of flow in the left pulmonary artery after cavopulmonary connection.
The postoperative course of a 15-month-old girl who underwent a bilateral bidirectional cavopulmonary connection was complicated by a left chylothorax and left hemidiaphragm paralysis. Two-dimensional and Doppler echocardiography revealed complete flow reversal in the left pulmonary artery. This flow abnormality was confirmed by angiography. Multiple aortopulmonary collaterals had also developed and were coil embolized at the time of catheterization. Coil embolization of the collaterals, combined with relief of the chylothorax and diaphragmatic plication, reestablished forward flow in the left pulmonary artery.
Cardiac Catheterization↗
Doppler systemic venous flow patterns: changes in children with mild/moderate pulmonic stenosis.
To determine the usefulness of systemic venous flow patterns in patients with mild/moderate right ventricular hypertension, 17 patients with isolated mild/moderate pulmonic stenosis and 17 age-matched normal children were evaluated with pulsed Doppler echocardiography. Tricuspid valve, superior vena caval, and hepatic vein pulsed Doppler recordings were obtained with simultaneous respirometry and electrocardiography. Peak velocities and velocity-time integrals were measured for Doppler signals corresponding with ventricular systole, ventricular diastole, ventricular end systole, and atrial systole. The groups were similar in weight, heart rate, tricuspid inflow Doppler echocardiograms, and cardiac indexes. Compared with normal subjects, patients showed changes in respiratory variation for some superior vena caval and hepatic vein indexes. In addition, hepatic vein measurements made at ventricular end systole were significantly lower and measurements made at atrial systole were significantly higher in patients than in normal subjects. These changes in systemic venous flow patterns may provide a sensitive indicator of early right-sided heart dysfunction.
Adolescent↗
Intra-aortic balloon counterpulsation in newborn lambs infected with group B streptococcus.
To determine the efficacy of intra-aortic balloon counterpulsation (IABC) in neonatal group B Streptococcal (GBS) infection, we studied five lambs, 10-14 days old, weighing from 4.7 to 6.7 kg. The lambs were instrumented with arterial and venous catheters, and a 5 French intra-aortic balloon catheter with balloon volumes of 3-5 ml was inserted into the femoral artery. A continuous infusion of heat-killed GBS organisms was infused at a rate of 1.7 to 6.2 x 10(8) org/kg/min, until a 30-50% decrease in cardiac output was attained. IABC was then instituted for 30 minutes, hemodynamic measurements repeated, and IABC was stopped. GBS infusion caused significant decreases in cardiac output (282 +/- 62 vs. 165 +/- 38 ml/min/kg) and pH (7.39 +/- 0.02 vs. 7.33 +/- 0.06), and significant increases in mean pulmonary artery pressure (14.4 +/- 2.1 vs. 36.2 +/- 12.1 mm Hg) and pulmonary vascular resistance (1.20 +/- 0.38 vs. 5.08 +/- 1.49 mm Hg/L/min/kg). Institution of IABC during continuous GBS infusion significantly increased cardiac output (225 +/- 1.27 ml/min/kg). The institution of the IABC also resulted in a significant decrease in pulmonary vascular resistance (2.6 +/- 1.3 mm Hg/L/min/kg). The authors conclude that IABC improves cardiac output and decreases pulmonary vascular resistance in newborn lambs with GBS infection.
Animals↗
Effects of T cells on platelet-derived growth factor-like protein secretion from endothelial cells.
The cause of accelerated graft arteriosclerosis after heart transplantation is unknown. To examine whether the interactions of T cells and endothelial cells (ECs) could contribute to the cause of this phenomenon, T cells were co-incubated with human umbilical artery endothelial cells (HUAEC) and human vein endothelial cells (HUVEC) and the resulting conditioned medium supernatant was assayed for the presence of platelet-derived growth factor (PDGF)-like protein. PDGF-like protein secretion was significantly greater from HUAECs co-incubated with T cells at T-cell/HUAEC ratios of 30:1 (6.9 +/- 1.1 fmol/10(6) ECs) and 10:1 (6.0 +/- 1.1 fmol/10(6) ECs) than the combined background secretion from HUAECs and T cells incubated separately (3.6 +/- 0.8 fmol/10(6) ECs) (p less than 0.05). PDGF-like protein secretion above background levels from HUAECs was significantly greater, however, than from HUVECs co-incubated with T cells at T-cell/HUVEC ratios of 30:1 (1.0 +/- 0.4 fmol/10(6) ECs) and 10:1 (0.75 +/- 0.36 fmol/10(6) ECs) (p less than 0.05). In four experiments, preincubation of HUAECs with gamma-interferon induced HLA-DR antigen expression but actually caused a decrease in T-cell-induced PDGF-like protein secretion above background levels (3.0 +/- 0.6 fmol/10(6) ECs) when compared to nonstimulated HUAECs (4.0 +/- 0.4 fmol/10(6) ECs; p less than 0.05). PDGF-like protein secretion was minimal at 1 hour and increased over time to a maximum at 24 hours. The conclusion is that T cells are capable of inducing secretion of a very potent mitogen, PDGF-like protein, from endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)
3T3 Cells↗
Extracorporeal circulation in the fetal lamb. Effects of hypothermia and perfusion rate.
The poor prognosis of certain cardiac abnormalities detected prenatally by echocardiography has led some investigators to consider intrauterine cardiac surgery. Investigation into the efficacy of open cardiac procedures in-utero will require techniques for safe and effective fetal extracorporeal circulation and myocardial protection. We performed cardiopulmonary bypass in 8 fetal lambs to assess the feasibility of fetal cardiopulmonary bypass. Four fetuses underwent studies at 37 degrees C (Group I) and 4 at 25 degrees C (Group II). The aorta was clamped and cold crystalloid cardioplegia administered. Perfusion was carried out for 10 minutes each at high (95 +/- 18 cc/kg/min), moderate (67 +/- 10 cc/kg/min), and low (49 +/- 8 cc/kg/min) flow rates while hemodynamic and blood gas measurements were made. Total time on bypass averaged 57 min in Group I and 75 min in Group II. Four fetuses were successfully weaned from bypass following the study period. Fetal pO2 and oxygen saturation was very low at all flow rates in Group II and at low flow rates in Group I, indicating poor function of the placenta as an oxygenator at 25 degrees C and at low flow rates during normothermia. Lambs undergoing bypass at 37 degrees C had a progressive rise in pCO2 levels as flow decreased, while pCO2 was relatively normal at all flow rates at 25 degrees C. These studies serve as a starting point for the development of techniques to allow intrauterine correction of experimentally produced fetal cardiac lesions.
Animals↗
Congenital heart disease with ductal-dependent systemic perfusion: Doppler ultrasonography flow velocities are altered by changes in the fraction of inspired oxygen.
BACKGROUND: An unfavorable balance in systemic and pulmonary perfusion may occur in neonates with ductal-dependent systemic perfusion while being treated with prostaglandin E1 before surgical palliation or transplantation. At our institution, we adjust the fraction of inspired oxygen, with supplemental nitrogen if needed, to control pulmonary vascular tone and maintain systemic oxygen saturations near 75%. METHODS: We performed a noninvasive Doppler ultrasound study in 10 patients to determine whether velocity time integrals in the descending aorta and middle cerebral arteries and the peak velocity at the foramen ovale were acutely altered by changes in the fraction of inspired oxygen. Measurements were performed after 10- to 15-minute intervals of breathing 14% to 19%, 21%, and 35% oxygen. RESULTS: Antegrade descending aortic velocity time integrals did not change significantly when these patients breathed different amounts of oxygen; however, the retrograde velocity time integral in the descending aorta and the peak velocity of left-to-right shunt at the foramen ovale increased with increasing amounts of inspired oxygen. The ratio of antegrade to retrograde velocity time integrals in the descending aorta was greater with supplemental nitrogen than with supplemental oxygen. Middle cerebral arterial velocity time integrals were not significantly greater with supplemental nitrogen than with supplemental oxygen (p = 0.061). CONCLUSIONS: Systemic and interatrial Doppler velocities are acutely influenced by the fraction of inspired oxygen in neonates with ductal-dependent systemic perfusion.
Alprostadil↗
Methotrexate therapy in pediatric heart transplantation as treatment of recurrent mild to moderate acute cellular rejection.
We have used adjunctive therapy with methotrexate as treatment of recurrent mild-to-moderate acute cellular rejection and in an attempt to reduce rejection frequency and corticosteroid dosage. The purpose of this study was to review our experience with this treatment strategy. Eight patients, 13.1 +/- 1.1 years of age (mean +/- standard error of the mean) at the time of transplantation, were given methotrexate in addition to their standard triple therapy immunosuppression. Methotrexate was started at 6.2 +/- 2 months after transplantation after an average of 3.1 +/- 0.4 rejection episodes. Patients were given methotrexate weekly for 8 weeks at 2.5 or 5 mg orally every 12 hours for three doses (0.23 +/- 0.02 mg/kg/week). The time to resolution of rejection was 17.9 +/- 4 days after initiating methotrexate therapy. The number of rejections per month decreased significantly from the 2 months before methotrexate therapy (1.49 +/- 0.1) when compared with both the 2 months during methotrexate therapy (0.50 +/- 0.1) and the 2 months after methotrexate therapy was completed (0.44 +/- 0.3) (p < 0.005). Furthermore, when comparing total rejection frequency since transplantation and before methotrexate therapy to a follow-up period of 21.8 +/- 5 months after completion of methotrexate therapy, the rejection frequency was significantly less (0.81 +/- 0.2 versus 0.10 +/- 0.06 rejections/month) (p < 0.01). Prednisone dosage was also significantly less when comparing the time before methotrexate therapy to immediately after completion of methotrexate therapy (0.23 +/- 0.04 versus 0.15 +/- 0.03 mg/kg/day) (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Acute Disease↗
Murine monoclonal CD3 antibody (OKT3)-based early rejection prophylaxis in pediatric heart transplantation.
The purpose of this study was to review our experience with the use of OKT3 (a murine monoclonal CD3 antibody) used as immune prophylaxis for pediatric heart transplant recipients. Orthotopic heart transplantation was performed in 18 pediatric patients, 8 girls and 10 boys, ranging in age from 17 days to 17 years. OKT3 therapy was initiated intraoperatively at a dose of approximately 0.2 mg/kg and was administered at a dose of approximately 0.1 to 0.2 mg/kg/day for a period of 11.5 +/- 2.5 days. Daily average OKT3 levels were 1132 +/- 469 ng/ml. Side effects that occurred during OKT3 therapy were fever (59%), diarrhea (24%), headaches (24%), vomiting (18%), encephalopathy (12%), pulmonary edema (6%), and rash (6%). Infections occurred in 24% of patients, all within 6 months of transplantation. In the first year after transplantation, patients experienced 3.4 +/- 2.4 episodes of mild rejection and 1.0 +/- 0.8 episodes of moderate rejection. No patient experienced severe rejection. Five of the surviving 14 patients (36%) have been weaned from chronic steroid therapy, and 42% are being maintained on alternate-day prednisone at a dose of 0.06 +/- 0.02 mg/kg/day. Coronary artery disease developed in three patients; two of whom died. Actuarial survival was 83% at 1 year and 73% at 2 years. This report shows that OKT3 prophylaxis in pediatric heart transplantation can be used with acceptable short-term adverse side effects and overall survival.
Adolescent↗
Relaxation and imagery techniques without sedation during right ventricular endomyocardial biopsy in pediatric heart transplant patients.
Routine endomyocardial biopsies after heart transplantation can be performed in pediatric patients with the right internal jugular venous approach. To minimize hospital time, limit disruption of daily activities, and eliminate the need for sedation, biopsies in patients older than 7 years of age were done with relaxation and imagery techniques. No complications occurred with this method, and all patients tolerated the procedure well.
Adolescent↗
Impact of prolonged waiting times of neonates awaiting heart transplantation.
OBJECTIVES: This study analyzed waiting times and outcomes of neonates listed for heart transplantation at two medical centers from 1991 through 1994. STUDY DESIGN: Retrospective analysis was performed to examine waiting times, charges, morbidity, and outcomes. RESULTS: Of the 30 neonates listed for transplantation, 15 received hearts, with 10 late survivors. Waiting time increased from 25 +/- 8 days in 1991 and 1992 to 58 +/- 7 days in 1993 and 1994 (p < 0.01), and the hospital charge per patient increased from $118,300 +/- $31,500 to $198,700 +/- $25,400 (p < 0.05). Freedom from sepsis predicted receiving heart transplantation (p < 0.01). Lack of a preoperative central intravenous catheter, no preoperative mechanical ventilation, and A-negative blood type predicted heart transplantation survival (p < 0.05). The chances of receiving and surviving transplantation were the same in the two periods. There was a trend toward greater morbidity among neonates waiting more than 35 days. CONCLUSIONS: Waiting times and charges have increased significantly over the last 4 years. Patients who are free of sepsis, lack a preoperative central intravenous catheter, are not mechanically ventilated preoperatively, and have A-negative blood type have better outcomes.
Graft Survival↗