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In pediatric patients cardiac pacing has been traditionally carried out by the epicardial approach in Taiwan. This study was to define the long-term results of transvenous endocardial pacemaker therapy in growing children. From 1994 to 1997, patients with sympatomatic bradycardia referred for permanent pacemaker were enrolled. Permanent pacemaker was implanted under propofol anesthesia and direct puncture of subclavian vein and creation of prepectoral pocket. A total of 10 patients ( 5 male, 5 female) aged from 5 to 17 years (13 +/- 4 yrs), constituted the study population. Follow-up period ranged from 14 to 48 months (29 +/- 14 months) . Underlying rhythm disturbances and pacemaker type implanted were: complete atrioventricular (AV) block 5 (VDD pacemaker in 3 and VVIR in 2), sick sinus syndrome 2 (DDDR pacemaker in both), sick sinus syndrome with abnormal AV conduction 1 (WIR), long QT syndrome 1 (VVIR) and hypertrophic cardiomyopathy 1 (DDDR). Pacemaker dysfunction occurred in only one patient in whom the endocardial lead was fixed by absorbable thread with an aim to have more flexibility of the lead. The endocardial lead was dislodged but properly reimplanted about 3 months after the initial implantation. All patients had satisfactory lead sensing and pacing threshold during the long-term follow-up. The pacing threshold was much better than that usually neededfor epicardial leads. With growing, none have the problems of lead length. Quality of life was reported to be improved in all. Tranvenous permanent pacemaker implantation is feasible in children aged 5 or older The long-term efficacy is satisfactory. Physiological pacing using a single lead (VDD) is recommended for younger patients with impaired AV conduction.

Cardiac catheterization can be superfluous and risky for sick babies, infants, and young children with total anomalous pulmonary venous connection (TAPVC). This study assessed the accuracy of echocardiography in the clinical assessment of pediatric patients with TAPVC before cardiac surgery.A total of 15 consecutive patients with TAPVC treated between July 1, 1993, and December 31, 1999, were included in this retrospective study. Patients with TAPVC with heterotaxy syndrome were excluded. We assessed this cardiac anomaly preoperatively using plain chest roentgenograms, echocardiography, and magnetic resonance imaging. A combination of suprasternal, parasternal, subcostal, and apical four-chamber views and their tilting scans were employed for diagnosis and to trace the course of the anomalous pulmonary venous connection.Interatrial right-to-left shunt via atrial septal defects were documented by two-dimensional echocardiography with color Doppler mapping in all 15 patients. Patent ductus arteriosus was found in six patients. Cardiomegaly with enlargement of the right atrium and the right ventricle could be seen on plain chest roentgenograms and by echocardiography in all but two patients with infracardiac TAPVC. In all patients, the left innominate vein, coronary sinus or right atrium, and portal vein were the draining sites of supracardiac, cardiac, and infracardiac TAPVC, respectively. A pattern of continuous flow without phasic variation, which is suggestive of stenosis of the pulmonary vein, was found in two patients with infracardiac TAPVC with obstruction. The surgical findings were reviewed and correlated well with those of the echocardiography.In infants and children with TAPVC, the drainage sites and flow profiles of the pulmonary veins can be exactly determined by Doppler echocardiography preoperatively, which makes cardiac catheterization and angiocardiography unnecessary.

To investigate the usefulness of electron beam computed tomography (EBCT) in the preoperative detection and perioperative management of insidious concomitant primary tracheobronchial anomalies in patients with tetralogy of Fallot (TF).From July 1995 to October 1999, 88 children (38 girls, 50 boys) with TF were enrolled in this study. EBCT examinations provided information needed to plan management. The final diagnoses of airway abnormalities were correlated with the findings of bronchoscopy in five patients and confirmed during surgery.Fourteen (16%) of the 88 patients had associated primary tracheobronchial anomalies. Nine patients had tracheal bronchi, which were combined with tracheobronchial stenosis in two patients and with tracheal stenosis in one patient. Two patients had tracheal diverticulum, which was combined with lower tracheal stenosis in one patient. Two patients had congenital tracheal stenosis. Tracheomalasia was found in one patient. Three patients with ventilation difficulties died postoperatively. Special attention was given to the care of the diseased airways perioperatively, and the remaining 11 patients had a smooth course of hospitalization and discharge.Our results show that EBCT provides good delineation of both cardiac and tracheobronchial anomalies and suggest that it should be used perioperatively to detect associated airway anomalies in TF, to facilitate the design of an appropriate ventilation care strategy.

To study the epidemiology of leprosy in children in Taiwan.Taiwan, with a population increase from 3.3 to 21.7 million, several tides of immigration and national leprosy control programs, from 1910 to 1997.To collect and analyze the documents of Taiwan leprosy surveys and charts of the National Leprosy Control Center.Cumulative and new number of all-age and pediatric-age patients, prevalence rates, new case detection rates, and results of skin bacterial smears.The prevalence rates of all-age leprosy ranged between 1.54 and 3.22 per 10,000 population. The proportion of children among all-age patients reached the highest of 4.93% in 1966, dropping to 0% in 1984 and thereafter, until 1988 and 1991 when two and one pediatric-age patients appeared, respectively, following the influx of immigrants from leprosy-endemic countries. The rise and fall of new patients younger than 15 years and 15 years or older were slightly correlated (r = 0.935, p0.001). Detection and confirmation of leprosy in children are usually belated. Physicians should still be acquainted with the clinical diagnosis of leprosy since sporadic cases of leprosy can reappear, particularly among children coming from endemic countries.

To investigate the effects of 3-week versus 4-week administration of benzathine penicillin G (BPG) on the incidence of Group A streptococcal infections and the recurrences of rheumatic fever (RF).We started, in 1979, randomly allocating all patients with RF to a 3-week or 4-week BPG prophylaxis program. They were examined at the RF clinic, every 3 to 6 months, and at any time they did not feel well. During 1979 to 1989, throat cultures and sera for antistreptolysin O and streptozyme titers were obtained at each clinic visit. Chest radiographs, electrocardiogram, color Doppler echocardiograms, and acute phase reactants were obtained.Two hundred forty-nine patients fulfilled the revised Jones criteria and were followed until December 1991: 124 in the 3-week and 125 in the 4-week program. Their age, sex, weight, percentage with history of RF, severity of cardiac involvement, follow-up duration, and compliance to program were comparable. Eight hundred eighty throat cultures were collected in the 3-week program and 770 were collected in the 4-week program. Six hundred sixteen and 627 sera were determined in each program for antistreptolysin O, and 582 and 592 sera for streptozyme titers.True streptococcal infections occurred in both programs: 39 infections in the 3-week program, and 59 infections in the 4-week program (7.5 vs 12.7 per 100 patient-years). Four infections with no antibody response occurred in the 3-week program, and three such infections in the 4-week program. Nine RF recurrences occurred in 8 patients in the 3-week program, and 16 recurrences in 16 patients in the 4-week program. Prophylaxis failure occurred in 2 of 124 patients in the 3-week program, and in 10 of 125 patients in the 4-week program (0.25 vs 1.29 per 100 patient-years). The overall recurrences/infections rate in each program was comparable, 13.6% vs 15.5%, but the recurrences/ infections rate due to prophylaxis failure was higher in the 4-week program than in the 3-week program, 3.0% versus 9.7%.This 12-year prospective and controlled study documented that streptococcal infections and RF recurrences occurred more often in the 4-week program than in the 3-week program. The risk of prophylaxis failure was fivefold greater in the 4-week program than in the 3-week program.

To define the nature and course of left ventricular (LV) thrombi in pediatric patients, the charts and echocardiographic records of 32 pediatric patients with dilated cardiomyopathy from 1986 to 1991 were retrospectively reviewed. Five patients who were identified according to echocardiographic evidence of LV thrombi fulfilled the criteria of dilated cardiomyopathy. Systemic embolization occurred in three patients with LV thrombi who invariably died despite anticoagulant treatment. Although it was not statistically significant, patients with LV thrombi tended to have a lower ejection fraction compared to patients without LV thrombi. The morphology of LV thrombi in patients with systemic embolization showed nonprotruding features. Thus, children with dilated cardiomyopathy are at risk of developing LV thrombi and systemic embolization. Although it was not possible to identify the risk factors, the risk of developing LV thrombi and systemic embolization may be higher in patients with lower ejection fraction of the left ventricle.

Supraventricular tachycardia (SVT) is the most common cardiac arrhythmia in children. Atrioventricular (AV) reciprocating tachycardia utilizing an accessory pathway and AV nodal reentrant tachycardia (AVNRT) constitute a majority of SVTs. Radiofrequency energy ablation has recently become the treatment of choice in adults. Initial experience in pediatric patients in this Institute is reported in this study. Six consecutive patients (aged 5-22 years, mean age 13 years; 3 boys, 3 girls) with narrow-QRS SVT were studied from July to October in 1993. They had experienced symptomatic SVT for a mean period of five years (ranged from 1 to 15 years). Anti-arrhythmic agents, including beta-antagonists and calcium channel blockers, were unable to satisfactorily suppress these SVTs. Four of the six patients were shown to have a left-sided concealed accessory connection as the retrograde limb of the reentrant circuit. After identification of the earliest retrograde activation site, a steerable 7F catheter with a 4-mm-long electrode at the distal tip was placed within the left ventricle and positioned against the atrio-ventricular annulus. Another two patients were proved to have AVNRT. The ablation catheter was placed at the posterior/inferior aspect of the tricuspid annulus and guided by putative slow potential. Radiofrequency current was delivered at a power from 15 to 25W for four to six times with a mean duration of 40 seconds in patients with AV reciprocating tachycardia, and a single time in those with AVNRT. All six SVTs were successfully ablated. No complication was noted in any patient. Follow-up for three to seven months has indicated no recurrence of SVT.(ABSTRACT TRUNCATED AT 250 WORDS)

To compare the efficacy of injections of 1.2 million units of benzathine penicillin G given every 3 weeks versus every 4 weeks for secondary prevention of rheumatic fever, based on the long-term outcome of patients receiving such prophylaxis.A total of 249 consecutive patients with rheumatic fever, randomly assigned to either a 3-week or a 4-week regimen, were examined every 3 to 6 months, and followed for 794 and 775 patient-years, respectively.Compliance with each regimen was comparable: 83 (66.9%) of 124 patients in the 3-week group versus 92 (73.6%) of 125 patients in the 4-week group stayed in the program (p0.05). Streptococcal infections occurred less frequently in those receiving the 3-week regimen: 7.5 versus 12.6 per 100 patient-years (p0.01). Prophylaxis failed in 2 patients receiving the 3-week regimen and in 10 receiving the 4-week regimen (0.25 and 1.29 per 100 patient-years respectively; p = 0.015). Serum penicillin levels were adequate (or = 0.02 micrograms/ml) in 100 (56%) of 179 samples obtained 21 days after penicillin injection in the 3-week regimen, and in 51 (33%) of 155 samples obtained 28 days after injection in the 4-week regimen (p0.01). Of 71 patients with mitral regurgitation in the 3-week regimen, 47 (66%) no longer had the murmur; of 87 patients in the 4-week regimen, 40 (46%) no longer had the murmur (p0.05).This 12-year controlled study indicates that the outcome of patients with rheumatic fever is better with a 3-week than with a 4-week penicillin prophylaxis regimen. Greater emphasis and more widespread use of the 3-week regimen should be recommended.

Forty-nine out of 66 patients with Turner's syndrome and different karyotypes underwent full cardiological evaluations (physical examination, electrocardiography, chest X-ray and echocardiography). Congenital cardiovascular anomalies were found in 11 patients (22.4%). Among the cardiac anomalies in patients with Turner's syndrome, aortic malformations (aortic coarctation [27%], aortic stenosis [18%] and bicuspid aortic valve [18%]) were the most frequent. We observed that the most severe malformations were found in those with karyotype 45,X or 45,X/46,XX. No anomalies were detected in patients with the X isochromosome or those mosaic with the Y component.

Acute rheumatic carditis is a rare cause of ruptured chordae tendineae of the mitral valve. Such rupture could result in severe mitral regurgitation and in fatality. Surgical valvuloplasty or valve replacement is usually necessary. A 12-year old boy presented with acute rheumatic carditis, complicated with rupture of the chordae tendineae of the mitral valve leading to intractable congestive heart failure and cardiogenic shock. He was successfully treated by a simple repair of the chordae and by mitral valvuloplasty.

Seven out of 829 pediatric cardiac patients (0.84%) were found to have sinus node dysfunction (SND) over the past seven years. Of the seven patients, three had structurally normal hearts. One of these three patients had long QT syndrome. In four patients, structural heart disease was noted. In three of these four patients the sinus node dysfunction was attributed to cardiac surgery. The age of onset of SND ranged from four months to eight years. Presenting symptoms and signs included syncope, near-syncope, seizure and congestive heart failure. Two patients were asymptomatic. Five patients had episodic sinus pause. Sinus or junctional bradycardia was noted in four patients. Three had tachy-bradycardia. High grade atrioventricular block was noted in one patient. Treadmill exercise test revealed a nonsustained ventricular tachycardia in two patients. All seven patients were found to have prolonged maximal corrected sinus node recovery time. Prolonged intra-atrial conduction time was found in three, prolonged AV nodal conduction time in one, and prolonged His-Purkinje conduction time in one patient during the electrophysiologic study. All seven patients showed abnormal results in intrinsic heart rate study. Anti-arrhythmic drugs were prescribed. During the follow-up study, no patient died, but two patients received a pacemaker implantation. Because of the extent of their conduction system diseases, it is recommended that patients with SND should be thoroughly investigated.

Balloon pulmonary valvuloplasty (BPV) is a well accepted treatment for moderate and severe pulmonary stenosis. However, the efficacy of BPV in treating mild pulmonary stenosis is still unanswered. Therefore, the efficacy of BPV in treating patients with mild pulmonary stenosis was compared to that in treating patients with moderate or severe pulmonary stenosis. A total of 46 patients with pulmonary stenosis were arbitrarily divided into 3 groups; Group I consisted of 9 patients with a pressure gradient less than 40 mm Hg, Group II consisted of 5 patients with a pressure gradient ranged from 40 to 50 mm Hg, and Group III consisted of 32 patients with a gradient greater than 50 mm Hg. Following BPV, the gradient reduced significantly in all 3 groups (p less than 0.05 in each group). The efficacy of BPV in the 3 groups was evaluated and compared by two parameters; one is the percentage of gradient reduction, the other is the right ventricular pressure ratio (RV post-bpv/RV pre-bpv). The percentage of gradient reduction in Group I, II, and III were 28 +/- 20, 55 +/- 17 and 70 +/- 9% respectively. The right ventricular pressure remained 84 +/- 11, 59 +/- 16, and 46 +/- 12% of pre-valvuloplasty level in Group I, II and III respectively. If the efficacy of BPV was compared among the 3 groups. Groups III had the best efficacy and Group I had the worst.(ABSTRACT TRUNCATED AT 250 WORDS)

To delineate the influence of maturation process on diastolic events of cardiac cycle, we had performed M-mode and Doppler echocardiography in 120 normal subjects aged from 1 hour to 16 years. The isovolumic relaxation period (IVRP, msec), defined as the time interval between the aortic valve closure to the mitral valve opening, was not statistically different in various age groups. Different equations based on individual ranges of cycle length (CL) were disclosed for each of three different age groups, demonstrating a positive linear correlation between IVRP and CL. On the contrary, an equation showing a linear correlation between diastolic total period (DTP, msec) and CL could be applied to all age groups: DTP = 0.58 x CL-75.2 (r = 0.89, p less than 0.001). Similarly applicable to all age groups, the duration of early diastolic filling (D-F, msec) changed with DTP in all age groups by an equation: D-F = 0.57 x DTP + 0.11 (r = 0.93, p less than 0.001). Ratios between the maximal velocity of early (E) and atrial (A) diastolic filling increased gradually with age. This was largely due to an increase in E with maturation, suggesting a depressed early diastolic filling in the young hearts. We conclude that the patterns of diastolic relaxation and filling are heterogeneously affected by the degree of maturation and represent the net results of complex interactions between changing inactivation properties and loading status at various stages.

Atrial flutter (AF) is a potentially dangerous arrhythmia in children, which is difficult to be converted into sinus rhythm by drug therapy alone. In four young patients (3 had history of cardiac surgery, 1 had Ebstein's anomaly), the AF which had failed to medical therapy was converted into sinus rhythm by an intracardiac atrial pacing: In two patients the AF was terminated by atrial pacing alone, and in the other two the AF was converted into sinus rhythm by atrial pacing after procainamide infusion. In all patients an entrainment of AF was observed during the atrial pacing, which favored a reentrant mechanism for the AF in these patients. Evidences of sinus node dysfunction were observed in all three postoperative patients. We conclude that atrial pacing with or without procainamide infusion is an effective method for the conversion of atrial flutter. In addition, for patients with AF and concomitant sinus node dysfunction, this method can ensure the patients' safetiness.

A child with congestive heart failure was found to have a paroxysmal ventricular tachycardia (VT) without structural heart disease. This wide QRS tachycardia had an atrioventricular dissociation and a QRS pattern of right bundle branch block and left axis deviation. The tachycardia did not respond to lidocaine or procainamide but instantly responded to verapamil therapy. This VT could be initiated or terminated by either atrial or ventricular pacing during electrophysiologic study. The endocardial biopsy showed that there was myocardial hypertrophy with mild degree of interstitial fibrosis. This entity of ventricular tachycardia often occurs in young people with no overt heart disease but with subclinical endomyocardial changes.

From June 1988 to May 1989, 444 throat swab specimens were tested with an enzyme immunoassay kit for rapid diagnosis of group A streptococcal pharyngitis. The results were compared with those of throat culture method. The rapid test was positive in 37 of 42 culture-positive specimens and negative in 379 of 402 culture-negative specimens, thus yielding a total agreement of 93.7%, sensitivity 88.1%, specificity 94.7%, positive predictive value 61.7%, negative predictive value 98.7%. According to this practical application, we suggest that enzyme immunoassay test can be applied in outpatient clinics by busy pediatricians for rapid diagnosis of group A streptococcal pharyngitis.

The choice of a valved conduit or a valve in the right ventricular outflow tract remains a problem. We propose to reconstruct the pulmonary valve inside the patient's own pulmonary trunk by autologous pericardium in tri-semilunar fashion with concomitant formation of the sinus of Valsalva and commissure. This operation was carried out on a 7-year-old girl suffering from Fallot's tetralogy with an absent pulmonary valve. The ventricular septal defect was repaired and the pulmonary valve reconstructed as above. The postoperative cross-sectional echocardiogram, color Doppler echocardiogram and angiogram showed a pliable tri-semilunar valve across the pulmonary outflow tract without regurgitation. It is concluded that firstly, the sinus of Valsalva is indispensable for a stentless semilunar valve to be competent; secondly, reconstruction of the semilunar valve inside the pulmonary trunk by autologous pericardium is recommended for the absent pulmonary valve syndrome, but the long-term fate of this pericardial valve awaits further evaluation.

Nineteen patients with pulmonary valvular stenosis and two with aortic valvular stenosis, aged 20 days to 12 years, were studied before and after balloon dilatation valvuloplasty (BDV) by M-mode, 2-D, pulsed wave (PW) and continuous wave (CW) Doppler, and color flow mapping echocardiography. In those with pulmonary stenosis, a dome-shaped valve was found in 16(84%) of 19 cases before BDV, and the valve remained dome shaped only in 4(27%) of 15 after procedure (P less than 0.001). Restricted valve motion which was noted in 18(95%) of 19 before BDV, persisted only in 2(13%) of 15 after procedure (P less than 0.001). Thickening of the pulmonic valve and poststenotic dilatation of the main pulmonary artery stayed almost unchanged. The pressure gradient across the pulmonic valve measured by cardiac catheterization and CW Doppler agreed well (r = 0.862). Echocardiographic evidence of pulmonary regurgitation was detected in 1(25%) of 4 patients before, and 7(50%) of 14 after BDV. In two patients with aortic stenosis, the echocaardiograms showed the valve was thickened and dome-shaped. Following BDV, echocardiographic evidence of mild aortic regurgitation was observed only in one patient who had had such a regurgitationn before BDV. The diameter of the valve annulus measured on 2-D echo and angiocardiograms correlated well (r = 0.912), and it stayed unchanged following BDV. It is concluded that 2-D and Doppler echocardiographic examinations proved to be useful in the measurement of valve annulus, delineation of stenotic semilunar valves and monitoring of the efficacy of BDV.

Activation of the complement system by iodinated contrast medium (ICM) infusion was studied in 25 children with congenital heart disease who received 76% Urographin during angiocardiographic studies. Total hemolytic activity (CH50), C1q, C3, C4 and C3 activator were determined before and 2, 5, 10, 15 and 20 minutes after Urographin infusion. Results showed that CH50 decreased in 16 patients (64%), C3 in 12 patients (48%), C3 activator in 12 patients (48%), C1q in 11 patients (44%) and C4 in 11 patients (44%). No side effect was encountered in all patients. It is therefore concluded that both the classic and alternative complement pathways could be activated by ICM and no causal relationship could be found between the presence of complement activation and the occurrence of adverse reactions to ICM infusion.