Coarctation of the aorta in children at Siriraj Hospital.

A retrospective analysis of 33 children who were diagnosed to have coarctation of aorta at Siriraj Hospital between January 1989 and December 1998 was undertaken. There were 21 males (64%) and 12 females (36%). Their ages ranged from one day to 11 years (median 2 months). The majority of the patients (78.8%) were presented early within the first year of life. The predominant clinical manifestations were congestive heart failure (69.6%), systemic hypertension of the upper extremities (36.3%) and decreased femoral pulses. Chest roentgenogram revealed cardiomegaly (70%) and increased pulmonary blood flow (84%), reflecting congestive heart failure and associated left-to-right shunting. Electrocardiogram showed normal pattern (33.3%), right ventricular hypertrophy (33.3%), left ventricular hypertrophy (22.2%) and biventricular hypertrophy (11.2%). The younger the patient is, the more right ventricular predominance is demonstrated. According to the echocardiogram and/or aortogram, juxtaductal type was found in 51.5 per cent, postductal type in 27.3 per cent and preductal type in 21.2 per cent. Medical management included prostaglandin E1 infusion in a newborn baby presented with low-cardiac output state, anticongestion and antihypertension, if indicated, followed by surgical correction. The result of coarctectomy with end-to-end anastomosis with or without arch augmentation was good. The operative mortality rate was 5 per cent. The overall mortality in the present study was 9 per cent. The most common causes of death were multiorgan failure and pulmonary infection. Residual coarctation was found in 5 per cent.

Radiofrequency catheter ablation in pediatrics: experience at Siriraj Hospital.

Tachyarrhythmia is one of the life threatening cardiac electrophysiology problems in children. It also affects quality of life of the patients. Radiofrequency catheter ablation (RFCA) has made a significant impact in the treatment of tachyarrhythmia since 1989. The present report is the first and largest report in Thai children. There have been 24 RFCA procedures in 21 children since it was initially performed at Siriraj Hospital from January 1996 to December 1999. The electrophysiology studies and medical records were analyzed retrospectively. Median age and weight at the time of the procedure were 11 (1.1-13) years old and 38.8 (6.8-78.2) kg respectively. The presenting symptoms were palpitation 66.7 per cent, presyncope 16.7 per cent, congestive heart failure and cardiogenic shock 8.3 per cent, syncope 4.2 per cent, and chest pain 4.2 per cent. Median duration of symptom was 3.5 (0.1-8.0) years. The underlying cardiac arrhythmias were Wolff Parkinson White (WPW) syndrome 50 per cent, concealed accessory pathway 16.7 per cent, atrioventricular node re-entry tachycardia (AVNRT) 16.7 per cent, atrial ectopic tachycardia (AET) 12.5 per cent, and WPW with AVNRT 4.2 per cent. The median fluoroscopy time and procedure time were 25 (4-145) minutes and 125 (60-320) minutes respectively. The median tachycardia cycle length was 332.5 (220-460) seconds. The immediate success rate was 21/24 (87.5%) procedures. The procedural complication was 1/24 (4.2%). Two patients (8.3%) had recurrences of tachycardia and were successfully controlled with antiarrhythmic drugs. Conclusion: RFCA is a safe, effective, and curative procedure with high success rate for pediatric tachyarrhythmias.

Radiofrequency catheter ablation: 5 years experience at Siriraj Hospital.

Between February 1995 to May 2000, 626 consecutive patients underwent radiofrequency catheter ablation for various types of cardiac arrhythmia. The mean age was 41 years, range 1-85 years. Mapping and ablation were guided by intracardiac electrogram and anatomical approaches. The initial success, compliction, recurrent and final success rates are shown below:- [table; see text] Conclusion, RFCA is an effective treatment and should be considered as first line treatment for certain tachyarrhythmia.

Limitation of transthoracic echocardiography in the diagnosis of congenital heart diseases.

Nowadays, it has been widely accepted that echocardiography is the most efficient, non invasive diagnostic tool to diagnose congenital heart diseases. However, cardiac catheterization remains the gold standard to diagnose and obtain hemodynamic data prior to cardiovascular surgery. In order to find out the accuracy of transthoracic echocardiography in relation to the anatomical diagnosis of congenital heart diseases, 175 consecutive patients who underwent diagnostic cardiac catheterization during January 1999 to December 1999 were reviewed. All of them had complete echocardiographic studies prior to the procedure. The male to female ratio was 1.06:1. The median age at the time of echocardiography was 3.36 (0.01-28.8) years old. The indications of the cardiac catheterization were to demonstrate cardiovascular anatomy 64 per cent, to obtain pulmonary artery pressure and pulmonary vascular resistance 13.7 per cent, and to get both information 22.3 per cent. Tetralogy of Fallot (23.4%) was the most frequent cardiac malformation, followed by complex congenital heart diseases (22.3%), simple left to right shunt (12%), pulmonary atresia with ventricular septal defect (8.6%), tricuspid atresia (5.7%), simple d-transposition of great arteries (4%), etc. From cardiac catheterization; 49 cases (28%) revealed additional data which were surgically important, 3 cases (1.7%) resulted in different diagnoses, and 3 cases (1.7%) revealed additional information which was not surgically important. Inadequate imaging technique (36 cases, 65.5%) and limitation of technique (19 cases, 34.5%) were the reasons for missing anatomical findings of transthoracic echocardiography. Age at the time of echocardiography was not a significant factor affecting the accuracy. Persistent left superior vena cava, multiple aorto-pulmonary collateral arteries, pulmonary artery anatomy, and coronary artery anatomy were the most frequent cardiac lesions misdiagnosed by transthoracic echocardiography that were somewhat surgically important. The incorrect echocardiographic diagnoses were aorto-pulmonary window, patent ductus arteriosus, and vascular ring. Thorough and extensive echocardiographic scanning coupled with cooperative or adequately sedated patients by an experienced operator using an efficient echocardiographic machine might improve the accuracy of transthoracic echocardiography in the diagnosis of congenital heart diseases.

Utility of intraoperative transesophageal echocardiogram in congenital heart disease.

Intraoperative transesophageal echocardiogram (TEE) has improved the perioperative outcome in adult patients. The purpose of the current study was to assess the benefit of intraoperative TEE in patients with congenital heart disease undergoing surgical correction (repair). The results of the patients who had consecutively undergone intraoperative TEE during their congenital heart surgery between January 1998 to June 2000 were reviewed. There were 104 patients (whose ages ranged from one week old to 50 years old (median 5 years old) and their weights from 3 kg to 79 kg (median 15 kg). A significant impact was said to have occurred if these findings prompted a change in surgical procedure following a prebypass study or rebypass for repair of a residual defect. Prebypass TEE had a significant impact in seven patients (6.7%). TEE could be used as a guide to help repair in three patients. The postbypass TEE examination had a significant impact in 15 patients (14.4%). Of these 15 patients, eight were detected primarily by TEE examination. The group of patients in whom TEE had the most significant impact was in patients who had surgery related to the repair of the atrioventricular valve (complete or partial atrioventricular (AV) canal repair, Ebstein's anomaly; 9 out of 22 patients; 41%). A less significant impact was found in surgery for other complex congenital defects (single ventricle or complete transposition of great arteries; eight out of 46 patients; 17.4%). TEE had limited impact in simple congenital lesion. Intraoperative TEE is valuable in the perioperative care of patients with congenital heart defects. We found the most benefit in patients with complete or partial AV canal and Ebstein's anomaly.

The Fontan operation: experience at Siriraj Hospital.

Seventy five patients underwent modified Fontan operation at Siriraj Hospital from October 1987 to December 1998. Cardiology data was analyzed retrospectively. Four patients' data was unavailable. Median age at operation was 9.7 (1.8-34) years old. Tricuspid atresia accounted for 38 per cent of the patients. Ten patients (14.1%) died in the acute post operative period due to consequence of low cardiac output. Another 3 patients (4.2%) expired in the intermediate and late post operative period. Age at operation, pulmonary artery size, pre-operative oxygen saturation, and mean pre-operative pulmonary artery pressure were not different between those who survived and those who died. Abnormal pulmonary vein, atrioventricular valve regurgitation, and underlying ventricular morphology statistically affected the acute survival of modified Fontan operation. Intraoperative aortic cross clamp time, and post operative mean pulmonary artery pressure on day 0, 1 and 2 post operation were found statistically shorter and lower in the survival group. Survival rate at 5 years was 83 per cent. Modified Fontan operation is the final palliative operation of choice for low risk single ventricle physiology in our institution with acceptable outcome. Thorough pre-operative hemodynamic and anatomic studies and staging modified Fontan procedure may include a higher number of candidates and improve the outcome of the operation.

Intermediate term follow-up on transcatheter closure of atrial septal defects by Amplatzer septal occluder.

BACKGROUND: Surgical repair of secundum atrial septal defect (ASD) is a safe, widely accepted procedure with negligible mortality. However, it is associated with morbidity, discomfort and a thoracotomy scar. As an alternative to surgery, a variety of devices for transcatheter closure of ASD have been developed. OBJECTIVES: We report our clinical experience with transcatheter closure of ASD using the Amplatzer Septal Occluder, a new occlusion device with intermediate term follow-up. PATIENTS & METHOD: Patients having ASD met established two-dimensional echocardiographic criteria for transcatheter closure were selected. ASD size was measured by transesophageal echocardiogram (TEE) and balloon occlusion catheter (stretched diameter). The Amplatzer's size was chosen to be equal to or 1 mm less than the stretched diameter. The device was advanced transvenously into a guiding sheath and deployed under fluoroscopic and TEE guidance. Once its position was optimal, it was released. TEE was undertaken to demonstrate the residual shunt. RESULTS: There were 26 patients with a mean age of 17.2 +/- 15.9 years old (2 to 60) and a mean weight of 22 +/- 37.5 kg. (10.7 to 62.5). The mean ASD diameter measured by TEE was 18.3 +/- 5.2 mm. and by stretched diameter was 22 +/- 7.5 mm. Four patients who had ASD stretched diameter over 32 mm were excluded because a larger device was not available. Devices were deployed in 22 patients with sizes from 9 to 30 mm (median = 22mm). Immediately after closure a tiny residual shunt was observed at the core of the device in each case. At 24 hours only two patients had a small (< 2 mm) shunt. One patient with fenestrated ASD had a device embolized into the right ventricle with successful removal and surgical closure. Patients were followed-up for a mean duration of 8 +/- 3.5 months (from 3 to 12 months). Complete occlusion was found in 20 out of 21 patients (95%). CONCLUSION: The Amplatzer Septal Occluder is a new device designed for closure of different sizes of ASD and can be easily and safely deployed. Our experience showed that this device could be used to close an ASD as large as 30 mm. The intermediate term follow-up also demonstrated an excellent closure result. Caution should be undertaken with patients who have a fenestrated atrial septal defect particularly at the septal rim.

Radiofrequency catheter ablation of Wolff-Parkinson-White syndrome: report of 83 cases from Siriraj Hospital.

We described the characteristics of patients and accessory pathway and showed our results of Radiofrequency catheter ablation (RFCA). There were 41 males and 42 females at a mean age of 36 years. Accessory pathway associated with Wolff-Parkinson-White (WPW) syndrome in our population was more prevalent on the right side which is different from previous reports. Most commonly associated heart disease was Ebstein's anomaly. Overall success rate was 96.4 per cent. Right free wall accessory pathway needed a longer procedure time and fluoroscopy time, higher radiofrequency power and more radiofrequency applications compared to other locations. Although the recurrence rate was 12 per cent, all patients with recurrence were successfully reablated. We also described the comparison of our result with previous studies. To our knowledge this is the first report in Thailand with a reasonable number of cases. RFCA is a very effective treatment of WPW syndrome in the Thai population and should be considered in symptomatic patients especially those who are refractory to medication.

Results of rapid two-stage arterial switch operation in patients with transposition of the great arteries: one-year postoperation.

The rapid two-stage arterial switch operation is an alternative therapy for patients with simple transposition of the great arteries who present beyond the neonatal period and have low left ventricular pressure. It provides normal ventricular function compared to the atrial switch operation. Between July 1994 and February 1997, there were 13 such infants who had rapid two-stage arterial switch operation performed at Siriraj Hospital. There was 1 late death (11 months after the operation). All 12 survivors (mean age 22.4 +/- 5.7 months) were clinically evaluated and had echocardiography performed at 14.8 +/- 4.9 months after the operation. All were asymptomatic. Echocardiogram revealed a residual small atrial septal defect (1 case), small ventricular septal defect (1 case), mild supravalvar neopulmonary stenosis (2 cases), bicuspid neoaortic valve without stenosis (2 cases), dilated neoaortic sinus of Valsalva (6 cases, 50%) and mild neoaortic insufficiency (11 cases, 91.7%). The left ventricular function was hyperdynamic after pulmonary artery banding and significantly decreased to normal level at the time of study (shortening fraction of 43.8 +/- 10.7 vs 29.2 +/- 3.8%, respectively, p = 0.0005). The wall thickness was significantly increased after pulmonary artery banding and decreased overtime (0.48 +/- 0.08 vs 0.32 +/- 0.05 cm, respectively, p < 0.0005). The left ventricular dimension was significantly increased both after pulmonary artery banding and at the time of study (2.06 +/- 0.42 vs 3.32 +/- 0.30 cm, respectively, p < 0.0005). The left ventricular mass was significantly increased after pulmonary artery banding and at the time of study (21.79 +/- 7.79 vs 33.08 +/- 7.40 g/m2, respectively, p = 0.0005). The mortality and morbidity of rapid two-stage arterial switch operation are low. However, long-term follow-up should be monitored.

Glucose-6-phosphate dehydrogenase deficiency in the newborn: its prevalence and relation to neonatal jaundice.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Thailand. This condition can cause acute hemolysis during oxidative stress and also severe hyperbilirubinemia in the newborn in some populations. Our aim was to study the prevalence of G6PD deficiency in relation to neonatal jaundice. We performed quantitative red blood cell (RBC) G6PD assay in the cord blood of 505 male subjects. Observation of jaundice and determination of bilirubin level as well as work up for other causes of jaundice were made in the G6PD deficiency group compared to a G6PD normal group. Questionnaires were also sent for further follow up to both groups. The results of the study were as follows: Sixty-one of 505 male (12.08%) had RBC G6PD deficiency (Group I). The rest (444 cases) had normal G6PD (Group II). In Group I, 49.15% developed neonatal jaundice, of which 28.82% were physiologic and 20.33% were pathologic jaundice. In group II, 23.68% developed jaundice; 16.51% were physiologic and 7.17% were pathologic jaundice, respectively. Onset of jaundice, date of peak bilirubin and peak bilirubin level in Group I and Group II were not statistically different. ABO incompatibility was associated with Group I in 17.24% and with Group II in 9.09%. Hospitalization day in Groups I and II were not statistically different. Other associated diseases were found in both groups, ie infection, congenital malformation, respiratory distress syndrome, but there was no significant difference in terms of jaundice. Phototherapy was required in 18.64% and 10.28% in Group I and II with a duration of 3.91 +/- 1.24 and 3.21 +/- 1.75 days, respectively. One case in Group I who was also premature received one exchange blood transfusion due to severe sepsis but he did not survive. One case in Group II who had polycythemia was successfully treated by partial exchange transfusion with plasma.