Ectopic atrial tachycardia in children

BACKGROUND AND PURPOSE

Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result in left ventricular dysfunction if not properly managed. In adults, EAT is mainly caused by diseased atrial myocardium and responds poorly to antiarrhythmic drugs. The characteristics of EAT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characteristics of their conduction tissue. We examined the natural history and treatment of EAT in children.

METHODS AND RESULTS

From June 1990 through June 1999, 24 children (8 girls and 16 boys; median age 4 mo [1 d-10 yr]) were admitted to our hospital with a diagnosis of EAT. Fifteen had healthy hearts, six had congenital heart disease, one had myocarditis, one had bronchopulmonary dysplasia with severe pulmonary hypertension, and one had hypertrophic cardiomyopathy. Thirteen patients presented with congestive heart failure. Only four patients had symptoms of prodromal airway infection. The maximum atrial rate was 244 +/- 66 beats per minute. Atrioventricular block was documented at least once during tachycardia in 10 patients. Warm-up or cool-down phenomenon was seen at the initiation or termination of tachycardia in thirteen patients. Primary pharmacologic treatment was attempted in all patients. EAT was initially controlled in all patients using digoxin plus propranolol (18 patients), propranolol only (4), or digoxin plus procainamide (2). EAT was controlled using medication in 22 patients. Fifteen patients had sinus rhythm but did not receive medication for 39 +/- 25 months. Two patients died of uncontrolled arrhythmia, and two of underlying disease. Recurrence was seen within 3 months after initial therapy in five patients. Surgery was performed to correct the underlying heart disease in three patients with frequently recurring EAT, all of whom remained tachycardia-free after surgery, without pharmacologic treatment. The spontaneous remission rate was 75% (18/24).

CONCLUSION

EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. Spontaneous resolution of EAT after medication in children was frequent (75%) in this series. The results of this study suggest that a step-wise approach using digoxin, a beta-blocker, and a class I antiarrhythmic drug may be the most effective treatment for EAT.

Dangerous impact--commotio cordis

Sudden death following blunt chest trauma is a frightening occurrence known as 'commotio cordis' or 'concussion of the heart'. It is speculated that commotio cordis could be caused by ventricular fibrillation secondary to an impact-induced energy that was transmitted via the chest wall to the myocardium during its vulnerable repolarization period. We describe a survivor of commotio cordis caused by a baseball. In this patient, an initial ventricular fibrillation was documented and converted by direct current defibrillation. Serial electrocardiographic changes (bifascicular conduction block and T wave inversion in precordial leads) were noticed in this patient. Our case suggested that coronary vasospasm might also play a role in commotio cordis.

Antioxidant activity of polyphenols from seeds of Vitis amurensis in vitro

AIM

To study the antioxidant action of five polyphenols (+) catechin, procyanidin B2, procyanidin B5, procyanidin B5 3'-O-gallate, and amurensisin isolated from the seeds of Vitis amurensis.

METHODS

The mouse liver homogenate lipid peroxidation assay was applied for the evaluation of the antioxidant activity in vitro.

RESULTS

(+) Catechin, procyanidin B2, procyanidin B5, procyanidin B5 3'-O-gallate, and amurensisin showed antioxidant activity with the IC50 values of 0.47, 0.25, 0.10, 0.02, and 0.03 mmol/L, respectively. The IC50 value of vitamin E used as a positive control was 0.13 mmol/L. The structural activity relationship was also analyzed. Procyanidins carrying a galloyl group possessed higher anti-lipid peroxidation activities. All dimers were found to be more potent than the non-galloylated momomer such as (+) catechin. However, the activity of the 4-->6 linked dimer seemed more preferable than 4-->8 linked dimer.

CONCLUSION

Procyanidin B5, procyanidin B5 3'-O-gallate, and amurensisin showed a more antioxidant activity than vitamin E did, and their activity is dependent on their substitution and polymerization patterns.

Procyanidins from the seeds of Vitis amurensis

Three procyanidins, procyanidin B-5 3'-O-gallate, vitisinol, and amurensisin, were isolated from the seeds of Vitis amurensis, whose structures were elucidated on the basis of spectral and chemical evidence. Vitisinol and amurensisin contain a spiro-type biflavanyl linkage and a biphenyl-lactone partial structure, respectively.

Comparison of intensive care of injured children between pediatric-based and non-pediatric-based intensive care units in a university hospital in Taiwan

Intensive care management of the injured child requires a multidisciplinary approach and meticulous attention to detail. However, the overwhelming majority of injured children are cared for by surgeons in surgical intensive care units (ICU) that see both adult and pediatric patients. There have been no previous reports of studies comparing the outcome in surgical ICUs (SICU) dealing with patients of all ages versus the outcome in pediatric ICUs (PICU). This study sought to determine differences in the outcome of pediatric intensive care between the SICU and PICU of our hospital. From Jan. 1989 to Aug. 1995, 118 children (68 boys and 50 girls), with an average age of 9.19 years (range: 3 months to 16 years), were admitted to our SICU. During the same period, 65 children (42 boys and 23 girls), with an average age of 5.04 years (range: 2 months to 16 years), were admitted to our PICU. Most of these patients received surgical intervention and were exclusively under surgeons' management. The decision to admit patient to the SICU or PICU was made by surgeon based on the availability of ICU beds. Pediatric risk of mortality (PRISM) score was used as a scoring system to assess disease severity in children. The most common cause for admission in both ICUs was traffic accidents. The average hospitalization duration in the SICU was 4.06 days (range 1 day to 23 days) and 3.34 days (range 1 day to 17 days) in the PICU. The average PRISM score was 7.87 (range 0-41) in the SICU and 6.48 (range 0-35) in the PICU. The overall mortality rate in the SICU was 12.7% (15/118) and 7.7% (5/65) in the PICU. There was a significant difference in patients' age and operative status but no significant difference in admission duration, PRISM score, and mortality rate between the SICU and PICU groups. The regression coefficients of the selected predictor variables and the impact on outcome showed one more score of PRISM would increase 1.5 fold of risk to become poor outcome while operation had lower risk (0.1 fold) to develop poor outcome. In conclusion, disease diversity and severity were similar among PICU and pediatric SICU patients in this study. The outcome was better in PICU patients although the difference was not statistically significant. The PRISM score is a useful measure to predict poor outcome in ICU patients after adjustment with confounders.

Double-lumen aortic arch with anomalous left pulmonary artery origin from the main pulmonary artery--bilateral persistent fifth aortic arch--a case report

Both double-lumen aortic arch (i.e., persistent fifth arch) and anomalous origin of the left pulmonary artery from the ascending aorta (failure of the development of the sixth arch) are rare diseases. They are frequently associated with cardiovascular anomalies. However, the co-occurrence of these two diseases has not been previously reported. We report such a case in a female baby with facial anomalies similar to conotruncal anomaly face syndrome.

Tricuspid atresia with persistent truncus arteriosus

The association of tricuspid atresia and persistent truncus arteriosus is a very rare congenital anomaly. We report a newborn with a prenatal diagnosis of tricuspid atresia, in whom associated type II persistent truncus arteriosus was found by postnatal echocardiography. The patient had mild cyanosis and developed heart failure soon after birth. Balloon septostomy was performed to enlarge the interatrial communication. However, her condition rapidly deteriorated and she died of sepsis and heart failure at the age of 14 days.

The role of pulmonary inflammation in the development of pulmonary hypertension in newborn with meconium aspiration syndrome (MAS)

1. There was no clear correlation between the tracheal aspirate cytokines and the elevation of pulmonary arterial pressure in newborn piglets with MAS. The use of dexamethasone significantly suppressed tracheal aspirate cytokines but did not significantly alter pulmonary arterial pressure. Dexamethasone significantly increased the cardiac stroke volume and blood pressure. 2. Early dexamethasone therapy (< 12 hrs) for one week in infants with MAS significantly improved pulmonary ventilation and facilitated weaning from mechanical ventilation. 3. The mechanisms for the improvement in cardiopulmonary status following early dexamethasone therapy in MAS remain unclear. An overall improvement in cardiac hemodynamics, along with a significant decrease in lung inflammation may be responsible for the improvement.

Laryngeal candidiasis in children

Candidiasis of the larynx is rare and often related to immunocompromised hosts. We here report a case of laryngeal candidiasis in an immunocompetent infant. The diagnosis was obtained by direct fibre-optic laryngoscopy with specimens submitted for culture. He received anti-fungal medication and was quite well at 1-year follow up. The pertinent literature is also reviewed.

Trifascicular block with intermittent complete atrioventricular block in a child

Trifascicular block, which consists of impaired conduction in the three main fascicles of the ventricular conduction system, may progress to high-grade or complete atrioventricular block. It rarely occurs in children with a structurally normal heart. We report a case of trifascicular block in a previously healthy 9-year-old girl. The patient presented with repetitive seizures. The electrocardiogram showed a complete right bundle branch block, left axis deviation, PR interval prolongation, and intermittent high-degree and complete atrioventricular block. She was successfully treated with a temporary pacemaker and her electrocardiogram returned to a normal sinus rhythm in 3 days. She has remained well over a 4-year follow-up. Although her cardiac enzyme levels were normal, the clinical course and electrocardiography findings suggested myocarditis. We emphasize the diagnosis of trifascicular block using electrocardiography; clinical outcome is good, if the patient is managed properly.

Myocarditis with complete atrioventricular block associated with herpes simplex virus infection: report of one case

Myocarditis with complete atrioventricular block is a very unusual complication of the herpex simplex infection. We report a 10-year-old boy infected very likely by the herpes simplex virus and who presented with high fever, erythema multiforme, complete atrioventricular block, and Adams-Stokes seizures. Emergent temporary pacemaker was performed for bradycardia. A sixteen-fold rise in herpes simplex antibody titer by a complement fixation method occurred within two weeks. Normal cardiac rhythm recovered 11 days later with a sequela of complete right bundle branch block after 2 years follow-up.

A study of the referral patterns of obstetric clinics and the performance of receiving neonatal intensive care units in Taiwan

To study the referral patterns of obstetric clinics, and the performance of receiving intensive care units measured by the survival of transported neonates, transport records were collected prospectively between July, 1991 and June, 1992. Two hundred and fifty-four transported neonates born in 51 obstetric clinics (level I units) in Tainan City and County, in southern Taiwan, were enrolled in this study. Nineteen percent of the transported neonates were very low birthweight infants (< 1500 g). Nearly equal numbers of them were transported to eight district hospitals (level II units) and to a tertiary center (level III unit), but these infants were 1.5 times more likely to die in a level II unit than a level III unit. In addition, equal numbers of infants assisted by mechanical ventilators were transported to level II and III units, but these infants were three times more likely to die in a level II unit than a level III unit (P = 0.006). Seventy-seven percent of the normal birthweight infants (> or = 2500 g) were transported to level II units, and the mortality in this group was 12.3% compared with 0% in those transported to the level III unit. Approximately 56% of these normal birthweight infants in level II units died of severe birth asphyxia. The referral patterns of level 1 units had an unfavorable effect on the survival of neonates requiring mechanical ventilation. Enhancing the skills of the staff in level I units to recognize and stabilize such infants, elevating the capability of level II units in treating some of these cases, and increasing the hospital beds for level III care are necessary to increase their chance of survival.

Long QT syndrome in children

Long QT syndrome is a disease that can cause syncope, seizures and sudden death. From June 1990 to June 1996, 11 children (male/female: 714; ages: 1 day-13 years with a median of 5.4 years) from different families were found to have long QT syndrome. Their corrected QT intervals (QTc) were 0.46-0.59 sec (median: 0.53 sec). All patients had normal hearing. One patient had Marfan syndrome with mitral valve prolapse. The presentation symptoms were: sudden death (2), seizures (6) and syncope (3). Their electrocardiogram abnormalities included: torsades de pointes (7), sinus bradycardia (4), T wave abnormalities (4), monomorphic ventricular tachycardia (2) and congenital complete atrioventricular block (1). All patients were treated with beta-blockers and one had pacemaker implantation. In a follow-up period of 0.5-6 years, 6 were symptom free, 1 died of ventricular tachycardia and 2 had recurrent syncope.

Cantrell's syndrome in an infant

Cantrell's syndrome is a rare combination of congenital midline thoracoabdominal defects and congenital heart disease. surgical repair can correct many of the anomalies. We report a neonate who presented with a short sternum, defective upper abdominal muscle, ectopic umbilicus, anterior diaphragmatic defect, ventricular septal defect and an intra-abdominal left ventricular diverticulum. Initially, the infant was treated with digoxin and diuretics for 5 months. Due to poor control of heart failure, one-stage surgical correction was performed with patch repair of the ventricular septal defect, ligation of left ventricular diverticulum and closure of the defects of the diaphragm and upper abdominal wall.

Pulmonary cavernous hemangiomatosis treated with interferon alfa-2a

Pulmonary hemangiomatosis is a rare, usually fatal disorder characterized by diffuse proliferation of blood vessels within the thorax. We describe a 7-year-old boy with cavernous-type pulmonary hemangiomatosis successfully treated with interferon alfa-2a. He presented with respiratory distress and hemoptysis that were alleviated during a 2-year follow-up period.

Infantile hypertrophic pyloric stenosis after surgery for esophageal atresia with tracheoesophageal fistula

Infants with esophageal atresia and tracheoesophageal fistula may have other associated anomalies. The development of infantile hypertrophic pyloric stenosis in the postoperative course of esophageal atresia with tracheoesophageal fistula is rarely reported. Because its symptoms may mimick postoperative complications such as gastroesophageal reflux or anastomotic stricture, the diagnosis may be delayed. We report an infant who had surgery for esophageal atresia with tracheoesophageal fistula at birth. The infant presented with nonbilious projectile vomiting at 4 weeks of age. Plain abdominal x-ray, barium upper gastrointestinal series and abdominal ultrasonography all supported the diagnosis of hypertrophic pyloric stenosis. The diagnosis was confirmed during surgery. After pyloromyotomy, the patient's condition improved.

Upper airway obstruction caused by vascular anomalies in children

Vascular ring or sling is one of the important etiologies for congenital upper airway obstruction in children. Between July 1988 and July 1995, a total of 92 children with stridor were initially evaluated by an esophagogram and two-dimensional echocardiogram. Seven children (7.7%) with variable types of vascular anomalies were diagnosed including pulmonary artery sling (2 cases), double aortic arch (1 case), right arch with left aberrant subclavian artery and ligamentum ductus (1 case), double aortic arch with one atretic arch (2 cases), and innominate artery compression of the trachea (1 case). The age at diagnosis ranged from 18 days to 3 years old. Only one patient was associated with an intracardiac anomaly. Five of the 7 patients were diagnosed as having laryngomalacia previously. Six patients had esophageal indentation on their esophagograms. Besides external airway compression, three patients also had intrinsic tracheal stenosis. Six patients received surgery because of severe respiratory distress. The patients' symptoms improved after surgery, but a premature baby died after a second operation for intrinsic tracheal stenosis at the age of 8 months.

Suprasellar embryonal carcinoma: report of one case

Intracranial embryonal carcinoma is a rare germ cell tumor found predominantly in the pineal region and, to a lesser extent, in the suprasellar region. The case of a 12-year-old female with a history of secondary amenorrhea for 6 months is reported; her symptoms included decreased visual acuity, dizziness and postprandial vomiting over a 1-month period. A huge suprasellar mass was found by computed tomography. Serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-HCG) levels were elevated. The tumor was subtotally resected; pathologic and immunocytochemical findings were compatible with embryonal carcinoma. The patient died three weeks after operation. The case is described and pertinent literature is reviewed.

Newtonian Dislocation Creep in Quartzites: Implications for the Rheology of the Lower Crust

Mechanical and microstructural evidence indicates that a natural and a synthetic quartzite deformed by Newtonian dislocation (Harper-Dorn) creep at temperatures higher than 1073 K and stresses lower than 300 megapascals. The observation of this creep in these materials suggests that the lower crust may flow like a Newtonian viscous fluid by a dislocation mechanism at stresses much smaller than those previously postulated.

Swertifrancheside, an HIV-reverse transcriptase inhibitor and the first flavone-xanthone dimer, from Swertia franchetiana

The first flavone-xanthone C-glucoside, swertifrancheside, was isolated from Swertia franchetiana, and its structure was elucidated on the basis of spectroscopic analysis as 1,5,8-trihydroxy-3-methoxy-7-(5',7',3'',4''- tetrahydroxy-6'-C-beta-D-glucopyranosyl-4'-oxy-8'-flavyl)-xanthone . This compound was a moderately potent inhibitor of HIV reverse transcriptase.

An equilibrium between distorted and undistorted DNA in the adult chicken beta A-globin gene

We have used single strand specific nucleases to map DNA distortion in the adult chicken beta A-globin gene. We have detected two structures of that kind and have mapped nuclease-cutting sites at one base resolution. One prominent site is centered at -190 relative to the RNA capping site and is positioned at the center of a stretch of contiguous C residues. The second site is near the first intron/exon junction (+620) and appears as a series of discrete 1-base-long enzyme-cutting sites. Based upon the pattern of nuclease cutting and the kinetics of nuclease cutting we conclude that the "poly(C)" stretch may assume a looped geometry in supertwisted DNA molecules which is similar to that proposed by Felsenfeld (Nickol, J. M., and Felsenfeld, G. (1983) Cell 35, 467-477). We show that S1 nuclease cuts within the intron occur mainly at the end points of polypurine segments and suggest that such end points may assume a distorted transitional geometry. We find that Neurospora crassa endonuclease cuts both the promotor and intron sites in linear DNA molecules but that in linear DNA the cutting process is limited by a first order conformation change of the DNA substrate. Based upon those kinetics we propose that in unstressed DNA, each of the two sites can convert between a distorted and undistorted geometry. In the enzyme assay buffer at 37 degrees C, the time constant for the equilibrium is nearly 10 h for the promotor site and 7 h for the intron.

The effect of female strain on identification of male mice carrying reciprocal translocations

Chemicals capable of inducing heritable chromosomal effects may be detected by the mouse heritable translocation test, which is based on the detection of a specific type of transmissible abnormality, namely, reciprocal translocation. Since mice carrying such a chromosomal abnormality usually have reduced fertility, they may be identified on the basis of fertility data. In the present study, the efficiency of two female strains for identifying CD-1 male translocation heterozygotes was examined. Thirty-three 10-wk-old CD-1 male mice were injected IP with triethylenemelamine (0.025 mg/kg/day) 5 days a wk for 5 wk. The treated males were then mated to untreated CD-1 females for 2 wk to produce progeny. The F1 males were raised to maturity, tested for fertility by using two female strains (CD-1 and B6C3F1), and analyzed cytogenetically. The cytogenetic analysis confirmed that 41 males were translocation heterozygotes and 125 were normal. Examination of the fertility data showed that in the test with CD-1 females all translocation heterozygotes were identified but 19 normal mice were identified as potential translocation carriers because of decreased fertility. In the test with B6C3F1 females, five translocation heterozygotes were not identified on the basis of fertility data, and 11 normal mice were misclassified as potential translocation carriers.