[Efficacy of percutaneous balloon aortic valvuloplasty for severe aortic valve stenosis in four infants under three months of age].

OBJECTIVE: To evaluate the outcome of percutaneous balloon aortic valvuloplasty (PBAV) for severe aortic valve stenosis in infants younger than 3 months of age. METHODS: Four infants under the age of 3 months (ranged from 34 to 87 days) underwent PBAV for severe aortic stenosis between June 2010 and March 2011 were included in this study. The weight of infants ranged from 2.8 to 4.8 kg. The peak systolic valve gradient, left ventricular ejection fraction (LVEF) and aortic regurgitation were measured in all patients just before and immediately after balloon dilation respectively. Patients were followed-up up to 1 month after PBAV. RESULTS: The aortic annulus diameter ranged from 7.0 to 8.8 mm. The ratio of balloon to aortic annulus diameter ranged from 0.86 to 1.00. PBAV was successful in all cases. The peak systolic valve gradient measured by Doppler echocardiography was (60.6 ± 15.2) mm Hg (1 mm Hg = 0.133 kPa) and LVEF was (47.6 ± 7.5)% before PBAV. Immediately after PBAV, the peak systolic valve gradient decreased to (29.5 ± 8.0) mm Hg (P < 0.01) and LVEF increased to (52.2 ± 18.9)% (P > 0.05). Two patients experienced significant bradycardia during PBAV and restored normal cardiac rhythm after cardiopulmonary resuscitation. At 1 month after PBAV, the peak systolic valve gradient measured by Doppler echocardiography was (36.5 ± 11.0) mm Hg (P < 0.05 vs. pre-PBAV) and LVEF was (81.0 ± 1.1)% (P < 0.01 vs. pre-PBAV). Only trivial to mild aortic regurgitation was detected post PBAV in the 4 patients. CONCLUSION: PBAV is a feasible palliative procedure for infants with isolated aortic valve stenosis without annular or ventricular hypoplasia.

[Adenosine for pulmonary vasodilator testing in children with idiopathic pulmonary arterial hypertension].

OBJECTIVE: The assessment of pulmonary vascular reactivity plays an important role in the management of idiopathic pulmonary arterial hypertension (IPAH). The aim of this study was to explore the indications and methodology of pulmonary vasodilator testing in children with IPAH. METHODS: From October 2009 to June 2011, a cohort of pediatric patients with IPAH in WHO functional classes II to III were enrolled in the study. Right heart catheterization was performed in all patients. After baseline hemodynamics were obtained, adenosine infusions were started at a dose of 50 µg/(kg·min), increased by 25 µg/(kg·min) at 2 min intervals to a maximum of 250 µg/(kg·min) or until a positive acute response. RESULTS: A total of 15 patients with IPAH were enrolled in the study. The mean age of the patients was 6.3 yrs. Mean pulmonary artery pressure (mPAP) was (67.1 ± 15.9) mm Hg. Pulmonary capillary wedge pressure (PCWP) was (9.7 ± 2.9) mm Hg. Pulmonary vascular resistance index (PVRI) was (17.9 ± 7.5) Wood U·m(2). Three patients were responders, defined as a fall in mPAP of at least 10 mm Hg to a pressure level of 40 mm Hg or lower. Twelve patients were nonresponders according to the same criteria. Five out of the 15 patients experienced adverse effects, including chest discomfort (n = 1), systemic hypotension (n = 3) and bradycardia (n = 1). All side effects abated within 30-60 s of the discontinuation of the adenosine infusion. CONCLUSION: Adenosine is an effective vasodilator in children with IPAH and can be used for safe and rapid assessment of vasodilator reserve in these patients.

Cheatham-Platinum stent implantation for pulmonary artery stenosis in children and adolescents: immediate and mid-term outcome.

BACKGROUND: NuMED Cheatham-Platinum (CP) stent implantation for pulmonary artery stenosis in children and adolescents has been rarely reported. This study aimed to evaluate the immediate and mid-term results of CP stent implantation for the treatment of pulmonary artery stenosis associated with congenital heart disease (CHD) in children and adolescents. METHODS: From August 2005 to May 2007, four consecutive pediatric patients with pulmonary artery stenosis associated with CHD underwent CP stent implantation. They were followed up, and transthoracic echocardiography was done for outcome evaluation. RESULTS: In the four patients, 5 stent placement procedures were performed and 7 CP stents were implanted (8-zig, 22-39 mm in length). All stents except one were successfully placed in the target lesions without displacement during the procedures. After the procedure, the systolic pressure gradient across the stenosis decreased from 36.67 ± 20.08 to 3.67 ± 3.20 mmHg (P=0.005), and the narrowest diameter of the stenotic segment increased from 6.97 ± 2.22 to 13.40 ± 4.40 mm (P=0.013). Two stents implanted in the left and right pulmonary arteries in patient 4 developed intrastent restenosis 6 months after the procedure, and the distal end of the main pulmonary artery also developed restenosis 26 months later. The results of the remaining stents have been stable without complications during a median follow-up of 34 months (range, 26-48 months). CONCLUSIONS: Our experience indicates that CP stent implantation is suitable for the treatment of pulmonary artery stenosis in children and adolescents with CHD. The immediate and mid-term results are encouraging, but long-term results demand further follow-up in more cases.

[Therapeutic effect of Cheatham-Platinum stent implantation for vessel stenosis associated with congenital heart disease in children and adolescents].

OBJECTIVE: Although NuMED Cheatham-Platinum (CP) stent was specifically designed to treat vascular obstructions associated with congenital heart disease (CHD), its application in pediatric patients is relatively uncommon, especially in the pulmonary artery stenosis. The aim of this study was to evaluate the immediate-, early- and intermediate-term results of CP stent implantation in the treatment of vessel stenosis associated with CHD in children and adolescents. METHODS: From August 2005 to May 2007, 5 consecutive patients (3 boys and 2 girls) diagnosed as vascular stenosis associated with CHD underwent CP stent implantation in our institution. One patient had native coarctation of the aorta (CoA) and four patients had pulmonary artery stenosis. The median age and weight of patients were 12 years (range 4 - 15 years) and 24 kg (range 20 - 51 kg), respectively. The CP stent and NuMED Balloon-in-Balloon catheter were selected according to digital subtracted angiography measurements. After checking for correct position by angiography, the inner balloon and outer balloon inflated successively to expand the stent to desired diameter. RESULTS: Totally 6 stent placement procedures were performed and 8 CP stents (8-zig, 22 - 39 mm in length) were implanted in these 5 patients. All stents but one in a case of right pulmonary artery stenosis were immediately successfully placed in the target lesions without displacement during the procedures. For this case, a repeat procedure was performed and a second CP stent was reimplanted successfully 11 months later. After the procedure, the systolic pressure gradient across the stenosis decreased from (43.43 +/- 25.61) mm Hg (1 mm Hg = 0.133 kPa) to (3.29 +/- 3.09) mm Hg (t = 4.320, P < 0.01) and the narrowest diameter of the stenotic vessels increased from (6.86 +/- 2.04) mm to (13.44 +/- 4.02) mm (t = -4.508, P < 0.01). The percentage of pulmonary artery flow to the ipsilateral lung increased from 11.0% and 13.0% to 47.5% and 52.2% after the procedure in 2 cases of unilateral pulmonary artery branch stenosis, respectively. The ratio of right ventricular to aortic systolic pressure decreased from 62.3% and 72.2% to 27.0% and 33.3% in 2 cases of bilateral branch pulmonary artery stenosis, respectively. Upper limb blood pressure of one case of native CoA dropped greatly from 206/133 mm Hg to 156/95 mm Hg. During a median follow-up of 20 months (range 13 - 34 months), the results have been stable without complications except 2 stents which developed intrastent restenosis 6 months after the procedure. CONCLUSION: Our experience suggests that the CP stent implantation is safe and feasible for the treatment of vessel stenosis associated with CHD in children and adolescents. The immediate-, early- and interim results are encouraging, but long-term results remain to be further evaluated and demand many more cases to be studied.

A novel mutation in the BMPR2 gene in familial pulmonary arterial hypertension.

BACKGROUND: Familial pulmonary arterial hypertension (FPAH) is an autosomal dominant disorder characterized by plexiform lesions of endothelial cells in pulmonary arterioles which leads to elevated pulmonary arterial pressure, right-sided heart failure and death. Heterozygous mutations in the bone morphogenetic protein type II receptor gene (BMPR2) have been found to underlie a majority of FPAH cases. More than 140 distinct mutations have been identified in FPAH cases and in idiopathic pulmonary arterial hypertension (IPAH) cases, but only one mutation has been reported in Chinese patients. METHODS: A three-generation pedigree of FPAH and another 10 patients with IPAH were collected. In the family, two of the 9 surviving and one deceased family member were diagnosed as FPAH. The entire protein-coding region and intron/exon boundaries of the BMPR2 gene were amplified by PCR using DNA samples from affected individuals. Direct sequencing of PCR products was performed on both the sense and antisense strands. To confirm the segregation of the mutation within the family and exclude the presence of the mutation in normal subjects, the relevant exon was amplified by PCR, followed by mutation-specific RPLP analysis. RESULTS: In the Chinese pedigree with FPAH an A-to-T transition at position 1157 in exon 9 of the BMPR2 gene was identified which resulted in a Glu386Val mutation. We confirmed the segregation of the mutation within the family and excluded the presence of the mutation in a panel of 200 chromosomes from normal subjects. No mutation was detected in BMPR2 in the other 10 patients with IPAH. CONCLUSIONS: This amino acid substitution occurs at a glutamic acid that is highly conserved in all type II TGF-beta receptors. The nearly invariant Glu forms an ion pair with an invariant Arg at position 491 thereby helping to stabilize the large lobe. Substitution of Arg at position 491 is the most frequently observed missense mutation in FPAH, but until now no mutations at position 386 have been found in FPAH. The predicted functional impact of the Glu386Val mutation and its absence in healthy controls support the mutation as the cause of FPAH.

[Exercise capacity evaluation after percutaneous balloon pulmonary valvuloplasty in children with pulmonary valve stenosis].

OBJECTIVE: To assess exercise capacity after percutaneous balloon pulmonary valvuloplasty (PBPV) in children with isolated pulmonary valve stenosis. METHODS: Treadmill exercise testing was performed in 46 children (6.3 +/- 3.1 years, ranging 1 to 12.5 years) with isolated pulmonary valve stenosis post PBPV and in 294 healthy children. Exercise capacity, change in heart rate, blood pressure, and electrocardiogram during exercise were observed. RESULTS: Post PBPV, the transvalvular gradient was below 25 mm Hg (1 mm Hg = 0.133 kPa) in all patients. The mean work capacity in post PBPV children was about 90 percent of that in healthy children. Heart rate and blood pressure response to exercise is comparable to healthy children. Factors associated with exercise capacity include age at operation and the ratio of balloon/pulmonary valve diameter. Exercise-induced uniform ventricular premature contraction in 5 children post PBPV and no ST segment change was observed. CONCLUSION: Exercise capacity post percutaneous balloon pulmonary valvuloplasty in children with isolated pulmonary valve stenosis was comparable to that in healthy children.

[Anomalous origin of the left coronary artery from the pulmonary artery: report on 10 cases].

OBJECTIVE: The anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary artery abnormality. This study aimed to investigate the clinical characteristics, diagnosis and treatment of the disorder. METHODS: The medical data, including common clinical presentations, the findings of the digital subtraction angiogram (DSA), echocardiograms and the electrocardiograph (ECG), surgical records and the outcome, of 10 children with ALCAPA between June 2001 and February 2005 were retrospectively reviewed. RESULTS: Diaphoresis, fantod, breathlessness and difficult feeding were commonly presented in the patients with ALCAPA. ECG, echocardiography and DSA examinations showed characteristic changes in these patients. The Takeuchi procedure was performed in 4 patients, direct aortic reimplantation in 4 cases and aortic reconstruction in 2 cases. After operation the symptoms of 8 patients were improved but 2 died. CONCLUSIONS: ALCAPA patients have characteristic clinical manifestations and lab findings. This is helpful in making an early diagnosis of ALCAPA. Early surgical treatment can improve the patients' outcome.

[Cardiac catheterization in neonates: experience in 26 neonates].

Cardiac catheterization is rarely performed in neonates in China. The medical records of 26 neonates who underwent cardiac catheterization in Shanghai Children's Medical Center from June 1994 to June 2004 were reviewed. These infants weighed 2300 to 4500 g (mean 3 400 +/- 500 g). Postnatal age ranged from 5 to 28 days (mean 15.2 +/- 8.7 days). Right heart ventricle angiography was performed in 24 cases, left heart ventricle angiography in 20 cases and pulmonary angiography in 6 cases. Balloon aortic septostomy (BAS) was performed in 10 cases. Twenty cases were diagnosed with complex cyanotic cardiovascular malformations and 4 with acyanotic heart disease. The implantation of a temporary cardiac pacemaker was performed in 2 cases. All diagnostic and interventional procedures were successfully performed. The catheterization-related complications occurred in 15.3% of the 26 cases, but without mortality. In conclusion, cardiac catheterization is an accurate and safe method for diagnosing complex congenital heart diseases in neonates. Interventional catheterization is useful in the treatment of complex congenital heart malformations.

[Risk factors for arrhythmia early after transcatheter closure of perimembranous ventricular septal defects].

OBJECTIVE: Perimembranous ventricular septal defects (PMVSDs) is the most common type of congenital ventricular septal defects (VSD), which accounts for 70% approximately 80% of VSD. The structure of PMVSDs is very complex, it is close to tricuspid valve, mitral valve and aortic valve. The atrioventricular (AV) node is located in the posterior upper membranous ventricular septum and branches into left and right bundle in the posterior lower margin. This increases the risk of transcatheter closure of PMVSDs. Arrhythmias is the common complication after transcatheter closure of PMVSDs. The present study aimed to identify the risk factors resulting in arrhythmias after transcatheter closure of PMVSDs in patients under 18 years of age to decrease the incidence of arrhythmias after the interventional catheterization. METHODS: A retrospective analysis was performed on the patients treated with transcatheter intervention from June 2002 to June 2004. Transcatheter closure of PMVSDs with Amplatzer membranous septal occluder and a domestic product was performed in 89 cases after obtaining consent themselves and/or their guardian or parents, 47 cases were males and 42 females. The age of the cases ranged from 3 to 18 years (mean 8.2 years) and the body weight ranged from 13 to 55 kg (mean 26.7 kg). They were all diagnosed as having PMVSDs with trans-thoracic echocardiography (TTE) before the interventional catheterization, the electrocardiographic (ECG) and chest X-ray (CXR) findings were recorded. A simultaneous care ECG and TTE were performed during operation in order to identify the effect of the transcatheter closure, the heart structure and functional changes and whether or not arrhythmias occurred, respectively. In 80 cases AGA Amplatzer membranous septal occluder was used and in 9 cases a domestic product was used. Follow-up was performed based on the echocardiography and ECG. RESULTS: The devices were successfully implanted in 89 cases; 11 cases (12%) developed various block of heart conduction within 5 days, which included first degree AV block in 1 patient, third degree AV block in 1, left anterior bundle branch block in 5, partial right bundle branch block in 4, complete right bundle branch block in 3, and 3 patients had two kinds of heart block. Eight patients were treated with corticosteroids, 6 of them recovered within 14 days, 1 patient within 1 month and in 1 case the problem shifted from first degree block and left anterior bundle branch block to left anterior bundle branch block 5 days later and that persisted for 6 months. It was found that the distance from upper margin of defects to the aortic valve < 3 mm, the diameter of ventricular septal defect > or = 8 mm, the diameter of device > or = 10 mm, blood pH < 7.35 and arteriovenous track building time after the success of the Seldinger technique > or = 60 min were independent predictors of post-closure arrhythmias. CONCLUSION: Arrhythmias remain the severe early complications after interventional catheterization for PMVSDs in patients under 18 years of age. Shortening of operation time, prevention of acidosis and strict selection of indications may be the most effective measures to prevent arrhythmias after transcatheter closure of PMVSDs in patients under 18 years of age.

[Effect of elastase inhibitor on pulmonary hypertension induced by monocrotaline].

OBJECTIVE: Pulmonary hypertension is a proliferative vascular disease characterized by pulmonary vascular structural remodeling. Until now, the pathogenesis of pulmonary hypertension is still not fully understood. Although considerable progress has been made, there is, to date, no cure for advanced pulmonary vascular disease. Recently, a number of studies suggest that endogenous vascular elastase (EVE) play a role in the vascular changes associated with pulmonary hypertension. The purpose of the study was to determine whether an elastase inhibitor might reverse advanced pulmonary vascular disease produced in rats by injection of monocrotaline. METHODS: One hundred and twenty male Sprague-Dawley rats were used in this study. The rats were divided into three groups: control, model and ZD-0892 groups. In the model and ZD-0892 groups, the rats were subjected to a single subcutaneous injection of monocrotaline (60 mg/kg) in the hind flank, while the rats in control group received an equivalent volume of 0.9% saline. From day 21, the rats in the ZD-0892 and model groups received twice-daily gavage tube feedings of either ZD-0892 at a dose of 240 mg/kg per day or its administration vehicle, while the rats in control group were subjected to an equivalent volume of 0.9% saline. On days 21, 28 and 35 post-injection, the elastolytic activity was measured with a fluorescence microplate reader and pulmonary artery pressure was detected via catheterization. Meanwhile, the lungs were evaluated morphologically, using the barium-gelatin perfusion technique. RESULTS: The injection of monocrotaline led to severe pulmonary hypertension in rats 21 days later and pulmonary artery elastolytic activity increased remarkably. A 1-week treatment with ZD-0892 resulted in declines in elastase activity. This was associated with significant declines in pulmonary artery pressure, decreases in muscularization of peripheral arteries and reductions in medial hypertrophy. After 2 weeks, elastase activity returned to normal level. Pulmonary artery pressure and structure were normalized. CONCLUSION: Increased elastase activity is important in the development of vascular changes and progressive pulmonary hypertension. ZD-0892 can suppress the elastase activity and completely reverse the fatal pulmonary hypertension induced by monocrotaline in rats.

[Transcatheter closure of secundum atrial septal defect in children].

OBJECTIVE: This study was undertaken to investigate the indication, methodology and complication of transcatheter closure of secundum atrial septal defect (ASD). ASD transcatheter occlusion techniques have become alternative to surgical procedures. A number of different devices are available for transcatheter ASD closure. The type and incidence of complications depend partially upon different devices. METHODS: A retrospective analysis was performed on the patients treated from October 1998 to January 2003. Transcatheter closure of ASD with Amplatzer septal occluder (ASO) was performed in 119 patients, of whom 3 patients were multiple ASD, 3 associated with pulmonary stenosis (PS) and 3 patent ductus arteriosus (PDA). The age of the cases ranged from 0.8 to 17 years (mean 7.5 +/- 2.8 years) and the body weight ranged from 6.7 to 88 kg (mean 23.7 +/- 7.8 kg). They all met with criteria for transcatheter closure. The balloon-stretched diameter of ASD was determined with fluoroscopy, ultrasound and measuring plate. A choice of device size was identical to or 1 approximately 2 mm larger than the stretched diameter (SD). A simultaneous PDA closure with device or balloon dilation was done in six cases associated with PDA or PS, respectively. Follow-up was performed based on the echocardiographic and clinical findings. RESULTS: In 119 cases examined with transesophageal echocardiography (TEE) or trans-thoracic echocardiography (TTE), ASD mean diameter was (12.9 +/- 5.6) mm (6.5 - 34.5 mm), pulmonary mean pressure was (29.0 +/- 5.0) mmHg (25.0 - 62.0 mmHg), and SD was (15.7 +/- 4.8) mm (8.0 - 38.0 mm). The diameters of these devices were (15.0 +/- 5.0) mm (8 - 38 mm). The devices were successfully implanted in 112 cases. Of them, 3 patients had multiple ASD with one device occlusion. 6 cases associated with PDA or PS were treated successfully with PDA occlusion or balloon dilatation, respectively. The immediate, one month and one year complete occlusion rates were 93.8% (105/112), 97.3% (109/112) and 98.2% (110/112), respectively. Residual shunt remained in 2 cases. No complication occurred except transient atrial premature beats and grade II type 1 A-V block in 5 cases (4.5%) and 1 cases (0.9%), respectively. The whole time period of the procedure ranged from 25 to 68 minutes. The total follow up period was from one month to 4.3 years. No unsatisfactory device position or embolization or clinical evidence of bacterial arteritis was found during the follow-up period. CONCLUSION: Transcatheter closure of secundum ASD using the ASO is a safe and effective alternative to surgical repair. Transcatheter closure of secundum ASD associated with small anterior, inferior or posterior rim is feasible using ASO. ASO can be performed in infants and young children only if the diameter of disk is smaller than the diameter of atrial septum. Multiple ASD is not the contraindication for intervention. If the diameter of ASD is over 36 mm, the device choice should depend on the maximum diameter of ASD determined with echocardiography. TTE is suitable for the smaller ASD and TEE for the bigger ASD. It is very important to avoid air embolism and atrial perforation during the procedure.

[Clinical analysis of diplopia in 68 cases with orbital fractures].

PURPOSE: To explore the cause of orbital fracture associated with diplopia by summarizing 68 cases,in order to offer reference for clinical treatment. METHODS: 68 cases of orbital fracture associated with diplopia were examined by maxillofacial surgeon and oculist,by analyzing the CT and X-ray films of whom to make clear the reasons of diplopia. RESULTS: Of the 68 cases,male was more than female,vertical diplopia was dominant,and generally with the changes of the orbital structure. CONCLUSION: The main cause of diplopia is for the changes of orbital structures. The doctors must take it seriously and give the patients timely treatment.

[Interventional therapy for complex congenital heart disease].

OBJECTIVE: The advances in interventional cardiac catheterization have changed the therapeutic strategy for many patients with congenital heart diseases. The aim of this study was to evaluate the role of therapeutic cardiac catheterization in the treatment of complex congenital heart diseases. METHODS: Balloon atrial septostomy (BAS) was performed in 59 children using Rashkind balloon catheter. Static balloon dilatation of the atrial septum was performed in 2 children with hypoplastic right heart syndrome. One child with pulmonary artery stenosis at the suture lines after arterial switch was treated with balloon dilatation. Percutaneous balloon pulmonary valvuloplasty (PBPV) and balloon angioplasty were performed in 15 children with tetralogy of Fallot (TOF). Transcatheter coil embolization was performed in 18 children with systemic to pulmonary collateral vessels and 5 children with B-T shunts before surgical procedures. Transcatheter closure of fenestration with Amplatzer septal occluder device was performed in 1 child who had undergone Fontan procedure. RESULTS: In 46 children with transposition of great arteries (TGA), the arterial oxygen saturation (SaO(2)) was increased from 0.57 +/- 0.17 to 0.76 +/- 0.13 (t = 14.58, P < 0.01) after BAS. The pressure gradients across left and right atrium were less than 2 mmHg. The created atrial septal defects were 5 - 20 mm in size. In 10 children with pulmonary atresia with intact ventricular septum (PA/IVS), the arterial oxygen saturation did not change after BAS (t = 1.57, P > 0.05), but the pressure gradients across left and right atrium were less than 2 mmHg. In children with TOF, the arterial oxygen saturation was increased by 15 percent after PBPV and pulmonary valvular stenosis was relieved. In 14 of 18 children with systemic to pulmonary collateral vessels and 5 children with B-T shunts, complete occlusion was accomplished and the procedures were successful. In the child who had undergone Fontan procedure, the fenestration was occluded successfully and no complication was observed. CONCLUSION: In management of complex congenital heart diseases, combination of surgical procedure and interventional catheterization therapy could be suggested to have better outcome.

[Arrhythmia in the long-term follow-up after intracardiac repair of tetralogy of Fallot].

OBJECTIVE: The long-term success of intracardiac repair of tetralogy of Fallot is hampered by the occurrence of arrhythmias. The aim of the present study was to determine the incidence of arrhythmias after intracardiac repair of tetralogy of Fallot and their correlation with surgical and clinical findings. METHODS: The study group consisted of 54 patients, 35 males and 19 females. They underwent repair at a mean age of 51 months (range 17 to 117 months). The median age at the time of study was 9.4 years (range 5 to 14 years), and the mean duration of follow-up was 4.3 years (range 2.8 to 9.0 years) after surgery. The follow-up study included routine ECG, 24 hour Holter, echocardiography and exercise testing. RESULTS: The incidence of ventricular arrhythmia was 33 percent, and 1 patient had non-sustained ventricular tachycardia. All patients with elevated right ventricular pressure had ventricular arrhythmias, and 28% of patients with normal right ventricular pressure had ventricular arrhythmias (P < 0.05). 53% of patients had significant ventricular arrhythmias when the duration of cardiopulmonary bypass was > or = 90 minutes, as opposed to 23% when it was < 90 minutes (P < 0.05). There was no significant difference in prevalence of ventricular arrhythmias between mild pulmonary regurgitation and severe pulmonary regurgitation (21% vs 40%, P > 0.05). No significant difference was found in the incidence of ventricular arrhythmias between follow-up in five years and more than five years (32% vs 34%, P > 0.05). Age at surgery correlated with the prevalence of ventricular arrhythmias (r = -0.221, P < 0.05). Eight patients (15%) had supraventricular arrhythmias. CONCLUSION: The frequency of ventricular arrhythmias correlated with elevated right ventricular systolic pressure, the duration of cardiopulmonary bypass, and the age at surgery. No correlation was found between pulmonary regurgitation and the duration of follow-up. Exercise-induced frequent multiform premature ventricular complexes were associated with abnormal hemodynamic status and high risk of ventricular tachycardia.

[Evaluation of physiological index on treadmill exercise testing of 294 healthy children in Shanghai area].

OBJECTIVE: Dynamic exercise is often used to evaluate the backlog function of cardiovascular system, and the treadmill test is a commonly used dynamic exercise protocol. The study aimed to assess the exercise capacity and cardiovascular response to treadmill exercise in healthy children, and create normal reference values of exercise testing in native children. METHODS: Two huadveds and ninety-four healthy children aged 5 to 14 years were tested using the Bruce protocol on treadmill. RESULTS: Mean exercise capacity in boys increased from 12.2 METs at the age of 5 to 6 years, to 15.2 METs at the age of 13 to 14 years. Mean exercise capacity in girls increased from 11.7 METs at the age of 5 to 6 years, to 12.6 METs at the age of 13 to 14 years. Sex difference was obvious in exercise capacity of children except those at the age of 5 to 6 years. There was no obvious correlation between exercise capacity and the ratio of weight to height. Maximal heart rate ranged from 187 to 235 beats/min. Systolic blood pressure increased gradually until peak exercise was achieved. The mean systolic blood pressure of boys at maximal exercise increased by 38.6 percent compared to resting level, and the girls increased by 34.4 percent. After maximal exercise, mean systolic blood pressure reached resting level in 6 minutes but diastolic blood pressure varied. All children had sinus rhythm at rest. No arrhythmia was recorded during treadmill exercise. However, arrhythmia was found in five children in early recovery period. The incidence of exercise-induced arrhythmia was 1.7 percent. CONCLUSION: Sex difference and age difference was obvious in exercise capacity. In the 21st century, the exercise capacity of children in Shanghai area has approached to the developed country. Using MET as the standardized criterion of exercise capacity is advantageous to standardize maximal or submaximal exercise workloads of all kinds of protocols. Exercise-induced arrhythmia in the early recovery period in children without structural heart disease may not be pathological, but it is necessary for those children to be followed-up.