Correlation between 6-min walk test and exercise stress test in healthy children.

AIM: To investigate the correlation between 6-min walk test (SMWT) and incremental treadmill exercise stress test (EST) as indicators for the functional capacity in children. METHODS: Healthy children aged 9-12 years were included. The anthropometric data, SMWT and EST were prospectively measured using the standard protocols. Various parameters were analysed to define the correlation between SMWT and EST. RESULTS: A total of 100 subjects (53 boys) aged 10.3 +/- 1.0 years participated in the study. The SMWT distance was 586.1 +/- 44.0 m. Height (r = 0.59, R(2) = 35%), length of the leg (r = 0.64, R(2) = 41%), heart rate at the end of SMWT (r = 0.59, R(2) = 35%) and heart rate difference at the end of SMWT (r = 0.71, R(2) = 50%) were found to have significant correlation with SMWT distance. The estimated maximal oxygen consumption (eVO2) obtained during the EST tended to be greater in boys than in girls. Among the parameters obtained during EST, maximal heart rate (r = 0.33, R(2) = 11%) and the eVO2 (r = 0.54, R(2) = 53%) were found to have significant correlation with SMWT. CONCLUSIONS: SMWT distance is significantly correlated with the eVO2 obtained during the EST. This indicates that SMWT is also one of the predictive markers for EST performance.

N-terminal pro-brain natriuretic peptide as a marker in follow-up patients with tetralogy of Fallot after total correction.

Patients with tetralogy of Fallot (TOF) after total correction usually have residual pulmonary regurgitation resulting in right ventricular (RV) dilatation and dysfunction. This study was performed to evaluate N-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting RV dilatation and RV dysfunction in TOF after total correction. Twenty-one patients with TOF after total correction (12 males and 9 females, 12.06 +/- 2.54 years old) underwent echocardiography, cardiac magnetic resonance imaging (MRI), and blood sampling for NT-proBNP. Mean time after total correction was 7.59 +/- 2.30 years. From cardiac MRI study, mean right ventricular end diastolic volume index (RVEDVi) was 148.36 +/- 64.50 ml/m2 and mean right ventricular ejection fraction (RVEF) was 35.50 +/- 10.50%. Right ventricular dilatation was considered if RVEDVi was >108 ml/m2 and RV dysfunction was considered if RVEF was <40%. A plasma NT-proBNP level of 115 pg/ml was identified by receiver operating characteristic analysis in predicting RV dilatation and/or dysfunction. At this value, the sensitivity and specificity for predicting RV dilatation, RV dysfunction, and both RV dilatation and dysfunction were 71 and 100%, 71 and 71%, and 83 and 78%, respectively. In conclusion, plasma NT-proBNP level may be helpful in follow-up patients. Plasma NT-proBNP levels >115 pg/ml can be used as a marker in the detection of RV dilatation and dysfunction.

Left main coronary occlusion from Takayasu arteritis in an 8-year-old child.

Takayasu's arteritis (TA) is a chronic systemic inflammatory disease that usually affects the aorta and its primary branches and occasionally the coronary arteries. We report the case of an 8-year-old girl who was presented with chest pain and was referred to our institution with the presumptive diagnosis of pneumonia and sepsis. Ultimately, the patient's chest pain was attributed to myocardial infarction secondary to coronary occlusion from TA. She underwent a successful stenting of the left main coronary artery with sirolimus-eluting stent. In a review of the literature, we discuss the demographic profile, clinical and radiographic findings, and available therapeutic options.

Beraprost therapy in children with pulmonary hypertension secondary to congenital heart disease.

We present a report on children with severe pulmonary hypertension secondary to congenital heart disease who received 6 months of beraprost therapy. The children had an increase in intracardiac left-to-right shunt and a reduction of the pulmonary-to-systemic vascular resistance ratio, whereas the pulmonary artery pressure was not significantly changed.

Chromosome 22q11 deletions in patients with conotruncal heart defects.

We performed this study to determine the frequency of 22q11 deletions and associated phenotypic features and abnormalities in conotruncal heart defects. Sixty-one patients with conotruncal heart defects, including tetralogy of Fallot (TOF; n = 32), pulmonary atresia/ventricular septal defect (PAVSD; n = 12), double-outlet right ventricle (DORV; n = 5), transposition of the great arteries (TGA; n = 4 ), truncus arteriosus (TA; n = 4), subpulmonary ventricular septal defect (SPVSD; n = 3), and interrupted aortic arch (IAA; n = 1), were enrolled in this study and screened for 22q11 deletions by the fluorescence in situ hybridization technique. Phenotypic features and associated abnormalities, including submucosal cleft palate, abnormal facies, square nose, nasal voice, abnormal ears, long and slender fingers, delayed development, mental retardation, delayed growth, short stature, and hypocalcemia, were examined in these patients. Nine of 61 patients (14.8%) had 22q11 deletions, including 100% of IAA, 50% of TA, 33.3% of SPVSD, 33.3% of PAVSD, and 3.1% of TOF. Deletions were not detected in DORV and TGA. In all patients with 22q11 deletions, > or =1 phenotypic features or associated abnormalities were observed. A subgroup of patients with IAA, TA, SPVSD, and PAVSD associated with phenotypic features or abnormalities warrants evaluation for the presence of 22q11 deletions.

Thromboembolic complications in Thai pediatric patients.

Sixty patients with thromboembolic complications from 1987 to 1997 at the Department of Pediatrics, Ramathibodi Hospital were retrospectively studied. Twenty patients were infants and 40 patients were children and adolescents with a mean age of 18 days and 8 years, respectively. The sites of thromboembolic complications were in the central nervous system, 27.5 per cent; skin as purpura fulminans or necrotic lesions, 24.5 per cent; gangrene of the toe, finger or colon, 19 per cent; deep vein thrombosis, 16 per cent; and other sites such as heart and lungs, 13 per cent. Most of them had triggering conditions (80%) and underlying diseases (76.7%) causing thromboembolism. The low levels of either antithrombin III, protein C or protein S were found in 42 per cent (15/36). The management included administration of standard or low molecular weight heparin if not contraindicated, replacement of fresh frozen plasma 10 ml/kg twice a day and treatment of underlying and triggering conditions. The fatality rate was 15 per cent (9/60). Subsequent episodes of thromboembolism occurred in 6 patients including: pulmonary emboli in one patient with protein C deficiency who refused warfarin administration, deep vein thrombosis in 2 patients with unidentified etiology, and necrotic skin lesions in 3 patients with vasculitis who did not respond to treatment. In conclusion, a comprehensive investigation and specific treatment for patients with thromboembolic complications are emphasized in order to prevent recurring episodes.

Residual patent ductus arteriosus shunting after single Gianturco coil occluding.

Transcatheter occlusion with Gianturco coils has become the treatment of choice for small patent ductus arteriosus (PDA). Coil occlusion was attempted in 20 patients with ductus diameter less than 4 mm who did not require other cardiac surgery. Sixteen of 20 patients had successful implantation. The mean age was 4.2 years. Their mean weight was 14.1 +/- 5.9 kg. The mean ductus diameter was 2.21 +/- 0.91 mm (range 1-3.7 mm). Nine patients had complete occlusion but 7 had residual shunting immediately after the procedure. However, 4 patients had spontaneous resolution of residual shunts at 6 months after the procedure. The other 3 who had diameter of ductus greater than 3 mm still had significant residual shunt at 6 months and 1 year after the procedure. The second coil was successfully implanted in one of these 3 patients and the closure of PDA was accomplished. We concluded that the second coil should be implanted if the ductus diameter is greater than 3 mm and significant residual shunt is still demonstrated angiographically after the first coil implantation.

Factors affecting mortality in Ebstein's anomaly of the tricuspid valve.

Ebstein's anomaly of the tricuspid valve is a relatively uncommon congenital heart defect. Twenty-one patients (11 boys and 10 girls) with Ebstein's anomaly were reviewed regarding clinical characteristics and factors related to the outcome of this lesion. Their ages at presentation ranged from 1 day to 13 years (median = 11 months). Eleven patients presented in infancy period, 6 of them were neonates. Common clinical findings were systolic murmur (85.7%) and cyanosis (57.1%). Laboratory findings included cardiomegaly on chest X-rays (95.2%), right bundle branch block pattern (76.2%) and right atrial enlargement (61.9%) on electrocardiography. Diagnosis and grading of severity were established by echocardiography. Among 21 patients, 4 were lost during follow-up. Seventeen patients were followed for 3-72 months. Six patients (28.6%) required surgery, 5 of whom died following surgery. Two patients died during the medical follow-up. Factors affecting cardiac death were the younger age at presentation, onset of cyanosis in infancy period, associated PS or PA, the lower insertion of the septal leaflet of the tricuspid valve and the higher ratio of the combined area of right atrium and atrialized right ventricle to that of functional right ventricle and left heart chambers.

Disseminated intravascular coagulation findings in 100 patients.

A retrospective study of 100 patients with disseminated intravascular coagulation from 1993 to 1997 is reported. Forty-five patients were neonates with a mean age of 12.6 days and 55 patients were infants, children and adolescents with a mean age of 6 years and 3 months. Most of them (91.5%) had complicated underlying conditions which included congenital anomalies, prematurity, malignancy, hematological and various diseases. Additionally, every patient had triggering conditions commonly identified as gram-negative septicemia. Bleeding and thromboembolic manifestations were found in 59.4 per cent and 19.8 per cent, respectively. The laboratory findings revealed red blood cell fragmentation, 89.6 per cent and thrombocytopenia, 85.8 per cent. Natural anticoagulants were studied in a few cases and revealed low levels of antithrombin III and protein C. The prompt effective management included treatment of underlying diseases, identification and relief of triggering conditions, correction of thrombocytopenia and coagulopathy, and fully supportive care. The overall case-fatality rate was 41.6 per cent which was not correlated with age, underlying diseases, triggering conditions, manifestation of bleeding, thromboembolism or shock, and exchange transfusion. However, a significant lower case-fatality rate was found in patients with positive culture (25%) as compared to those with sepsis and negative culture (51.7%) (p = 0.044). In addition, the febrile neutropenic patients, who showed good response to the administrated granulocyte-colony stimulating factor (G-CSF), survived from the DIC.

Indomethacin prophylaxis for patent ductus arteriosus (PDA) in infants with a birth weight of less than 1250 grams.

BACKGROUND: Very low birth weight (VLBW, less than 1500 g) and extremely low birth weight infants (ELBW, less than 1000 g) are the premature infants that are most likely to develop symptomatic PDA. Intravenous indomethacin has proven effective in prevention of PDA in many prospective trials. This strategy will be a useful adjunctive therapy for premature infants in Thailand. OBJECTIVE: To answer the following questions: 1. Will multiple doses of intravenous indomethacin, given to VLBW infants within the first day of life, effectively prevent the occurrence of symptomatic PDA? Are there any side effects or complications? 2. Will this strategy be more beneficial in ELBW? METHODS AND SUBJECTS: The study included thirty VLBW infants born at Ramathibodi Hospital, with birth weights ranging from 630 to 1230 g. They were randomized into 2 groups of 15 infants each. One group received 3 doses of intravenous indomethacin at the dosage of 0.2 mg/kg initially and then 0.1 mg/kg every 12 hours for 2 more doses; the second group received a placebo. The study was performed by a double blind control. RESULTS: Sixteen infants developed symptomatic PDA, 4 in the indomethacin group and 12 in the placebo group. The decrease in incidence of PDA is statistically significant. But when the data was analyzed separately for the VLBW and ELBW groups. The effects were only significantly different in ELBW but not yet significant in the VLBW group. There was a statistically significant difference in the incidence of severe intraventricular hemorrhage (IVH) (grade 3 or higher) in the ELBW infants. CONCLUSION: Intravenous indomethacin therapy given to VLBW infants with a birth weight of less than 1250 g decreased incidence of symptomatic PDA with no significant permanent side effects. The effect was markedly noticeable in ELBW infants. Incidence of severe IVH was also markedly decreased in the ELBW infants who received indomethacin.

Williams syndrome and the elastin gene in Thai patients.

Williams syndrome (WS) has long been known as a complex disorder of dysmorphic facial features, described as elfin face, mental retardation or learning disability, loquacious personality, and supravalvular aortic stenosis. The etiology is now known to be due to deletion of the elastin gene (ELN) on long arm of chromosome 7. Thai patients were previously reported by clinical diagnosis. This study reports the first two cases of WS with ELN deletion diagnosed by fluorescent in situ hybridization (FISH) technique. Clinically, hyperacusis is a common finding in WS associated with otitis media. Neither of the patients had hyperacusis, but one of them had bilateral sensorineural hearing loss, which to our knowledge, has never been reported.

Chromosome 22q11 deletion syndrome: the first three cases reported in Thailand.

The DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes were originally described as separate disorders due to different concerns regarding phenotypes. However, all these disorders have some common clinical manifestations, including congenital heart defect, facial anomaly, and developmental delay. It is now clear that most cases of these syndromes have a common cause resulting from microdeletion of chromosome 22q11. This study reports the first three cases of Thai children presented with developmental delays. All are females who were known cases of congenital heart diseases. Their minor facial anomalies were subtle and not previously recognized as of any syndromes. The chromosome study by fluorescent in situ hybridization technique yielded microdeletion of chromosome 22q11. Without known prevalence in Asian populations, except in Japanese children, further study for chromosome 22q11 deletion syndrome in Asian children with conotruncal heart defects, who also have minor facial anomalies or developmental delays, should be undertaken.

Balloon pulmonary valvuloplasty in children, one year follow-up experience at Ramathibodi Hospital.

UNLABELLED: Balloon valvuloplasty has become the treatment of choice in pulmonary valvular stenosis. The objective of this report is to review the experience of this procedure in children at the Department of Pediatrics, Ramathibodi Hospital in the past 4 years (1991-1994) with at least one year follow-up. During the study period, 19 children aged 2.1-14.3 years (mean 5.11 years) with the diagnosis of pulmonary valvular stenosis had successful pulmonary balloon valvuloplasty at this institution. The immediate peak systolic pressure gradient across the pulmonary valve by cardiac catheterization decreased from 92.05 +/- 46.92 to 34.26 +/- 25.30 mmHg, by Doppler from 78.58 +/- 26.55 to 34.83 +/- 15.60 mmHg. Peak pressure gradient across the pulmonary valve by Doppler of the last examinations, one to 4 years after the procedure (mean 1.9 years), was 23.05 +/- 9.40 mmHg in 17 patients. The mean ratio of balloon size and pulmonary valve ring was 1.06. One patient still has a residual gradient of 54 mmHg and two were lost to follow-up. No serious complication was encountered during the procedures. CONCLUSION: Balloon pulmonary valvuloplasty is effective in the management of children with valvular pulmonary stenosis. The intermediate term result is excellent.

Doppler echocardiography of normal and abnormal embryonic mouse heart.

To evaluate normal embryonic mouse heart development using Doppler echocardiography and to quantify changes in normal embryonic mouse cardiac function with increasing gestational age from the time of cardiac septation, a new method was applied using Doppler echocardiography. Trisomic embryos were screened to evaluate a model of abnormal cardiac anatomy. The development of the embryonic heart in mice has been well studied anatomically, but there are limited physiologic studies. A new method has been developed to assess the mouse fetal heart in a similar fashion to the current use of echocardiography in the chick embryo and the human fetus. This method was applied to normal mouse embryos known to survive and to abnormal trisomy embryos that die during gestation and have cardiac failure. To analyze early normal embryonic heart hemodynamics, Doppler echocardiograms were performed on n = 129 C57B1/6J mouse embryos from d 10 through 19 of gestation and 20 embryos with trisomy 16 (gestational d 11-14). The maximal blood velocities recorded at the inflow and outflow of the embryonic heart were analyzed for heart rate, peak early and peak late inflow and outflow velocities, and measurements were made of systolic ejection, filling, and other time intervals normalized for heart rate. A high velocity holosystolic or diastolic velocity with altered time intervals was identified as atrioventricular or semilunar valvular regurgitation, respectively. Inflow and outflow velocities increased with increasing gestational age. The time period of isovolemic contraction time was present before and undetectable after gestational d 17, whereas the total filling time increased. Ejection time and isovolemic relaxation time had no significant change. No valvular regurgitation was detected in normal embryos. These echocardiographic patterns are similar to those observed for human embryos. Abnormal Doppler findings were present (inflow or outflow valvular regurgitation) in 55% of trisomy 16 embryos. Echocardiographic data can now be obtained beginning at d 11 in the mouse embryo for analyses relating to abnormal heart development. A noninvasive technique may be invaluable to monitor the physiologic condition of embryos within a litter and to detect and monitor those embryos where heart defects may be expected. Qualitative markers of embryonic congestive heart failure such as valvular regurgitation may be present and detectable with structural valvular abnormalities or failing cardiac physiology. The mouse embryo is an appropriate animal model to analyze normal and abnormal mammalian heart development and function.

Diastolic function of the fetal heart during second and third trimester: a prospective longitudinal Doppler-echocardiographic study.

To generate normal charts of fetal cardiac inflow velocities and to assess physiologic changes of ventricular diastolic function, velocity waveforms of tricuspid and mitral valves were studied longitudinally in 49 fetuses in 4 week intervals from 14 weeks gestation to term. Doppler tracings were analyzed for: peak early (E) and peak late (A) inflow velocities, time velocity integral (TVI) of total inflow and A-wave velocity waveforms and heart rate corrected isovolemic relaxation time. E- and A-velocity as well as total- and A-wave-TVI of both valves increased significantly with gestational age (P < 0.001). Heart rate and A/E ratio decreased significantly with gestational age (P < 0.001). The ratio of A-wave TVI to total TVI of both valves and heart rate corrected isovolemic relaxation time (IVR) was constant suggesting unchanged diastolic function. This study provides normal charts for fetal cardiac inflow velocities. After 14 weeks of gestation all inflow velocities and their respective TVI's increased linearly in the growing fetal heart. There was evidence that diastolic function did not change. Area ratios and IVR should be used to determine changes in ventricular diastolic function, rather than velocity ratios.

Spontaneous closure of small ventricular septal defect first six months of life.

UNLABELLED: This study was designed to determine the incidence, types of the defects and the rate of spontaneous closure of the small ventricular septal defect (VSD) in infants who were born at Ramathibodi Hospital during the one year period April 1, 1991 to March 31, 1992. The diagnosis was confirmed by 2D-echocardiogram and Doppler and color flow imaging. RESULT: During the study period, the 15 infants diagnosed with small VSD, an incidence of 1.95 per 1,000 livebirths. The male to female ratio was 9 to 6. There were 11 muscular and 4 membranous VSD. Small VSD had a maximal diameter of 3 mm. of less. Spontaneous closure occurred in 9 to 15 (60%) during 6 months follow-up. The small muscular VSD spontaneously closed in 9 of 11 (82%) patients. CONCLUSION: This data supports the previous studies that the rate of spontaneous closure of small VSD is high and the muscular defect has a higher incidence of spontaneous closure.

Malignant pericardial tumor in childhood: a case report diagnosed by cross-sectional echocardiogram and magnetic resonance imaging.

Since primary malignant pericardial tumors are seldomly found in children, we reported a case with massive pericardial effusion. Pericardial tumor was diagnosed by cross-sectional echocardiogram. The extent of the tumor was well demonstrated by magnetic resonance imaging. The tumor was removed successfully and proved to be low grade fibrosarcoma. Modern technics can be very helpful in the diagnosis of pericardial tumor.

Cardiac beri-beri. Report of a case with an echocardiographic study.

An echocardiographic study in a patient with cardiac beri-beri has not been reported previously. We report serial studies in a 12-year-old boy with beri-beri. Tricuspid regurgitation was detected by Doppler in the early stage.