Dexrazoxane for preventing anthracycline cardiotoxicity in children with solid tumors.

This study attempted to assess the incidence and outcome of anthracycline cardiotoxicity and the role of dexrazoxane as a cardioprotectant in childhood solid tumors. The dexrazoxane group included 47 patients and the control group of historical cohort included 42. Dexrazoxane was given in the 10:1 ratio to doxorubicin. Fractional shortening and systolic and diastolic left ventricular diameters were used to assess the cardiac function. The median follow-ups were 54 months in the dexrazoxane group and 86 months in the control group. The mean cumulative doses of doxorubicin were 280.8+/-83.4 mg/m(2) in the dexrazoxane group and 266.1+/-75.0 mg/m(2) in the control group. The dexrazoxane group experienced significantly fewer cardiac events (27.7% vs. 52.4%) and less severe congestive heart failure (6.4% vs. 14.3%) than the control group. Thirteen cardiotoxicities including one cardiac death and 2 congestive heart failures occurred in the dexrazoxane group, and 22 cardiotoxicities including 2 cardiac deaths and 4 congestive heart failures, in the control group. Five year cardiac event free survival rates were 69.2% in the dexrazoxane group and 45.8% in the control group (P=0.04). Dexrazoxane reduces the incidence and severity of early and late anthracycline cardiotoxicity in childhood solid tumors.

Pulmonary hypertension in preterm infants with bronchopulmonary dysplasia.

BACKGROUND AND OBJECTIVES: With the increasing survival of preterm infants, pulmonary hypertension (PH) related to bronchopulmonary dysplasia (BPD) has become an important complication. The aim of this study was to investigate the characteristics and outcome of PH in preterm infants with BPD and to identify the risk factors for PH. SUBJECTS AND METHODS: We reviewed the records of 116 preterm infants with BPD cared for at a single tertiary center between 2004 and 2008. RESULTS: Twenty-nine (25%) infants had PH >2 months after birth. PH occurred initially at a median age of 65 days (range, 7-232 days). Severe BPD, a birth weight <800 g, long-term ventilator care and oxygen supplementation, a high ventilator setting, infection, and a patent ductus arteriosus (PDA) were related to PH based on univariate analysis (p<0.05). The infants who had longer oxygen supplementation were significantly more likely to have PH (odds ratio, 18.5; 95% confidence interval, 4.1-84.6; p<0.001). PH was improved in 76% of infants after a median of 85 days (range, 20-765 days). Four infants (14%) died. The death of 3 infants was attributed to PH. CONCLUSION: BPD was frequently complicated by PH. Although PH resolved in the majority of infants, PH in preterm infants with BPD can be fatal. Regular screening for PH and adequate management are required.

Long-term outcomes after an arterial switch operation for simple complete transposition of the great arteries.

BACKGROUND AND OBJECTIVES: Although coronary artery obstruction, aortic insufficiency (AI), and pulmonary stenosis (PS) have been reported after arterial switch operation (ASO), limited long-term studies on ASO exist. Our study aimed to examine long-term outcomes after ASO for simple complete transposition of the great arteries (TGA). SUBJECTS AND METHODS: All 108 patients with simple complete TGA who underwent ASO at Seoul National University Children's Hospital between 1987 and 2004 were enrolled. We retrospectively reviewed the patients' medical records and the results of various functional and imaging studies. RESULTS: Among 108 cases of ASO for simple TGA, 96 have been followed-up through the present time (mean follow-up duration was 11.7+/-8.6 years: range= 4 to 23 years). The 20-year rates of freedom from significant AI, PS, and coronary obstruction were 78.6%, 67.8%, and 95.8%, respectively. AI showed a tendency to progress as follow-up time increased in 21.4% of the population studied (p=0.014); however, AS, PS, and PI showed no such progression. Late coronary artery occlusion was not associated with the initial coronary arterial pattern. Re-operations were done for 13 patients (13.5%) at an average of 8+/-4.3 years after ASO. The survival rate was 96%, while the re-operation-free was 90% at 10 years and 83% at 20 years. Most patients showed normal physical growth with good activity {98%; New York Heart Association (NYHA) class 1 activity} and normal development (96%). CONCLUSION: Although most patients showed normal physical growth and development after successful ASO, meticulous long-term follow-up is necessary because of progressive AI and coronary complications.

Pediatric emergency room presentation of congenital heart disease.

BACKGROUND AND OBJECTIVES: Only a few studies have specifically investigated the reasons for emergency room (ER) visits in patients with congenital heart disease (CHD). The aim of this study was to identify the major reasons for ER presentation among patients with CHD that were acutely and seriously ill at a tertiary medical center in Korea. SUBJECTS AND METHODS: All 368 admissions of patients with CHD via the ER from 2003 to 2008 were enrolled. We conducted a retrospective study with review of the medical records. RESULTS: Eighty two patients were newly diagnosed as having CHD. Their major presentations were: symptoms of heart failure (41.5%), murmur (31.7%), and cyanosis (18.3%). There were 286 visits that were cases with known CHD. Their major presentations were respiratory tract infection (24.1%, 2.7+/-4.1 years of age), dysrhythmia (16.4%, 16.7+/-9.5 years), symptoms of heart failure (14.3%, 7.6+/-9.4 years), aggravated cyanosis (5.6%, 0.8+/-1.4 years), protein-losing enteropathy (4.9%), hemoptysis (4.5%), drug side effects (4.1%), and infective endocarditis (3.0%). There were significant correlations between the age distributions and major modes of presentation. Surgical treatments were required within 1 month in 38%, and 2.7% of all patients died during hospitalization. The patient group with respiratory infections and CHD showed the highest mortality (5.8%). Atrial flutter was the most frequent arrhythmia (70.2%) and 70% of these patients were post-Fontan surgery condition. The causes of heart failure in the patients with previous surgical repair were: pulmonary hypertension, myocardial dysfunction, valve regurgitation, and uncorrected lesions. CONCLUSION: Improved understanding of the common problems in the ER can help prepare clinicians to manage patients that present with CHD.

Septal dyskinesia and global left ventricular dysfunction in pediatric Wolff-Parkinson-White syndrome with septal accessory pathway.

INTRODUCTION: Echocardiographic studies have shown that some patients with Wolff-Parkinson-White (WPW) syndrome have myocardial dyskinesia in the segments precociously activated by an accessory pathway (AP). The aim of the present study was to determine the extent to which the AP contributes to global left ventricular (LV) dysfunction. METHODS: Electrophysiological and echocardiographic data from 62 children with WPW (age at diagnosis = 5.9 +/- 4.2 years) were retrospectively analyzed. RESULTS: The left ventricular ejection fraction (LVEF) of patients with septal APs (53 +/- 11%) was significantly lower than that of patients with right (62 +/- 5%) or left (61 +/- 4%) APs (P = 0.001). Compared to patients with normal septal motion (n = 56), patients with septal dyskinesia (n = 6) had a reduced LVEF (61 +/- 4% and 42 +/- 5%, respectively) and an increased LV end diastolic dimension (P < 0.001 for both comparisons). Multivariate analysis identified septal dyskinesia as the only significant risk factor for reduced LVEF. All 6 patients with septal dyskinesia had right septal APs, and a preexcited QRS duration that was longer than that of patients with normal septal motion (140 +/- 18 ms and 113 +/- 32 ms, respectively; P = 0.045). After RFA there were improvements in both intraventricular dyssynchrony (septal-to-posterior wall motion delay, from 154 +/- 91 ms to 33 +/- 17 ms) and interventricular septal thinning (from 3.0 +/- 0.5 mm to 5.3 +/- 2.6 mm), and a significant increase in LVEF (from 42 +/- 5% to 67 +/- 8%; P = 0.001). CONCLUSION: The dyskinetic segment activated by a right septal AP in WPW syndrome may lead to ventricular dilation and dysfunction. RFA produced mechanical resynchronization, reverse remodeling, and improvements in LV function.

A case of pulmonary thromboembolism associated with hypereosinophilia in a child.

Pulmonary thromboembolism is a very rare event in children, but the mortality rate is reported to be approximately 10%. The majority of children with thromboemboli have multiple risk factors, such as a catheter-related thrombosis, an infection, and a congenital prothrombotic disorder. Hypereosinophilia is very rarely associated with pulmonary emboli in adults; however, this condition has not been reported in children. We present a 12-year-old boy who had a pulmonary thromboembolism and deep vein thrombosis associated with hypereosinophilia and thrombocytopenia. The thromboembolism was managed with anticoagulant therapy and the hypereosinophilia resolved spontaneously.

Development of bilateral diffuse pulmonary arteriovenous fistula after Fontan procedure: is there nonhepatic factor?

The cause of pulmonary arteriovenous fistulas after a cavopulmonary anastomosis is not clearly known, but the previous studies regarding their causes have been focused mainly on the hepatic factors. We report two unusual Fontan cases with multiple bilateral pulmonary arteriovenous fistulas. One of them died of progressive hypoxia, and the other underwent multiple coiling. Our cases suggest that potentially lethal diffuse pulmonary arteriovenous fistulas may develop bilaterally in spite of balanced hepatic effluent flow to pulmonary circulation through factors other than a hepatic factor.

Cardiac dysfunction after renal transplantation; incomplete resolution in pediatric population.

BACKGROUND: Long-term data of cardiac function after renal transplantation (RT) are limited, especially in children. Thus, we evaluated the status of left ventricular hypertrophy and various indices of left ventricular (LV) function in pediatric RT patients. METHODS: Blood pressure, serum biochemical profiles, electrocardiogram, and echocardiogram of 32 pediatric patients (mean age, 15.5+/-4.4 years) who underwent RT 5.1+/-2.5 years before and 29 body surface area-matched control subjects were studied. RESULTS: Repolarization abnormalities shown on electrocardiogram of pre-RT patients improved significantly after RT (QTc dispersion 50.8+/-37.3 to 37.4+/-11.9 msec, P=0.009). Left ventricular hypertrophy with increased LV mass index of pre-RT patients regressed remarkably after RT (LV mass index 120.9+/-40.5 to 69.2+/-14.5 g/m2, P<0.001); still, LV mass was significantly higher in RT patients than the controls (54.0+/-9.6 g/m2, P<0.001). Compared with the controls, the RT patients showed diastolic dysfunction (lower E/A ratio and higher isovolumic relaxation time) and lower myocardial performance (higher LV Tei index and weaker strain pattern). Patients who had shorter duration of non-RT renal replacement therapy showed better LV function (lower LV Tei index and stronger strain pattern) in the long-term follow-up. CONCLUSIONS: Because cardiac dysfunction did not resolve after RT in pediatric population, regular evaluation for cardiovascular function after RT is required. Early RT may also be beneficial to global LV performance after RT.

Endothelial dysfunction and microvascular complications in type 1 diabetes mellitus.

We examined whether alterations in vascular endothelial function and early structural changes in atherosclerosis are associated with microvascular complications in patients with type 1 diabetes mellitus (DM). Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measurement were performed in 70 young adults (aged 19 to 35 yr), 48 with type 1 DM, and 22 normal controls. Patients with diabetes had a lower peak FMD response (7.8+/-3.9 vs. 11.1+/-1.9%, p<0.001) and increased IMT (0.51+/-0.10 vs. 0.42+/-0.07 mm, p<0.001) compared with controls. Twenty (41.7%) of the patients had microvascular complications including neuropathy, nephropathy, or retinopathy. In these complicated diabetic patients, we found a lower FMD response (6.1+/-2.5 vs. 9.9+/-3.5%, p=0.001) compared with diabetics without microvascular complications. The presence of microvascular complications was also associated with older age and longer duration of the disease. However, no differences were observed in IMT, body size, blood pressure, HbA1c, C-reactive protein, low-density lipoprotein or high-density lipoprotein cholesterol levels between complicated and non-complicated patients. Endothelial dysfunction and early structural atherosclerotic changes are common manifestations in type 1 DM, and endothelial dysfunction is thought to be an early event in the atherosclerotic process and important in the pathogenesis of microvascular complications.

QT interval prolongation and ventricular fibrillation in childhood end-stage renal disease.

Ventricular arrhythmia is a major cause of death in end-stage renal disease (ESRD). Corrected QT (QTc) interval prolongation, which is one of the predictors of ventricular arrhythmia, may be associated with ESRD. We report an 11-year-old boy who had ESRD with marked QTc interval prolongation and developed torsade de pointes with subsequent ventricular fibrillation during the induction of anesthesia. QTc interval was normalized completely after renal transplantation.

Kawasaki disease in Korea, 2003-2005.

PURPOSE: The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for the 3-year-period, 2003-2005. METHODS: The questionnaire for an epidemiologic survey on Kawasaki disease was distributed to all 102 Korean hospitals that conduct pediatric residency programs, and obtained data were analyzed upon receipt. RESULTS: The 9662 patients of Kawasaki disease from 85 hospitals that responded (response rate, 83.3%) consisted of 5877 males and 3785 females (male:female ratio, 1.55:1). The incidence rate per 100,000 children <5-year-old was 104.2 in 2003, 106.4 in 2004, and 104.6 in 2005 (average rate, 105.0). Their mean age of onset was 33.3 months, and the proportions of sibling cases and recurrent cases were 0.29% and 2.0%, respectively. Coronary arterial abnormalities were detected at follow-up by echocardiogram in 18.8% of all such cases including dilatations of 18.0% and aneurysms of 2.5%. CONCLUSION: The average annual rate of incidence, 105.0/100,000 in children <5-year-old is the second highest reported rate in the world.

Decreased left ventricular torsion and untwisting in children with dilated cardiomyopathy.

The purpose of this study was to analyze left ventricular (LV) torsion and untwisting, and to evaluate the correlation between torsion and other components of LV contraction in children with dilated cardiomyopathy (DCM). Segmental and global rotation, rotational rate (Vrot) were measured at three levels of LV using the two dimensional (2D) speckle tracking imaging (STI) method in 10 DCM patients (range 0.6-15 yr, median 6.5 yr, 3 females) and 17 age- and sex-matched normal controls. Global torsion was decreased in DCM (peak global torsion; 10.9 +/- 4.6 degrees vs. 0.3 +/- 2.1 degrees , p<0.001). Loss of LV torsion occurred mainly by the diminution of counterclockwise apical rotation and was augmented by somewhat less reduction in clockwise basal rotation. In DCM, the normal counterclockwise apical rotation was not observed, and the apical rotation about the central axis was clockwise or slightly counterclockwise (peak apical rotation; 5.9 +/- 4.1 degrees vs. -0.9 +/- 3.1 degrees , p<0.001). Systolic counterclockwise Vrot and early diastolic clockwise Vrot at the apical level were decreased or abolished. In DCM, decreased systolic torsion and loss of early diastolic recoil contribute to LV systolic and diastolic dysfunction. The STI method may facilitate the serial evaluation of the LV torsional behavior in clinical settings and give new biomechanical concepts for better management of patients with DCM.

Impaired vascular function in patients with Fontan circulation.

BACKGROUND: This study was performed to evaluate the endothelial function in Fontan patients, and to investigate the associated factors which influence the endothelial function in these patients. METHODS: Flow mediated dilatation (FMD) and nitroglycerin induced dilatation (NG) of the brachial artery, and intima media thickness (IMT) of common carotid artery (CCA) were measured in nonselected Fontan patients (n=44, age 5 to 29 years, median 14 years, 18 females) by means of high-resolution ultrasound according to the standard protocols. The results were compared to age and sex matched controls (n=25, age 5 to 27 years, median 13 years, 10 females). RESULTS: Fontan patients presented significantly reduced FMD and NG compared with controls (FMD; 6.5+/-2.4 vs. 11.1+/-1.4%, p<0.001, NG; 13.3+/-5.2 vs. 19.4+/-6.2%; p=0.035). Twenty two percent of Fontan patients presented pure endothelial dysfunction, and 34% of patients presented combined endothelial and smooth muscle dysfunction. Although there was no correlation between FMD and IMT, Fontan patients presented increased carotid IMT (0.44+/-0.07 vs. 0.38+/-0.06 mm, p=0.008). In multivariate analysis, duration of exposure to chronic hypoxia was inversely correlated with FMD (p=0.117, hazards ratio=1.294, 95% confidence interval=0.938-1.786). There was higher FMD in patients receiving angiotensin-converting enzyme inhibitors (ACEi) compared with those not receiving ACEi (7.0+/-2.5 vs. 5.5+/-2.2%, p=0.069). CONCLUSIONS: Endothelial dysfunction is more prevalent in Fontan patients compared with healthy controls, and the previous hypoxia is an independent factor. Although it is not statistically significant, those patients on treatment with ACEi seem to have better endothelial function.

Pediatric radiofrequency catheter ablation: results of initial 100 consecutive cases including congenital heart anomalies.

Radiofrequency catheter ablation (RFCA) has recently become a management option for pediatric tachycardia. We reviewed the records of a total of 100 patients (aged 10 months to 19 yr) who had undergone RFCA, from March 2000 to June 2004. Types of arrhythmia (age, acute success rate) were as follows: atrioventricular reentrant tachycardia (AVRT, 9.0+/-3.7 yr, 66/67), atrioventricular nodal reentrant tachycardia (AVNRT, 13+/-2.5 yr, 16/16), ectopic atrial tachycardia (6.4+/-3.3 yr, 5/5), junctional ectopic tachycardia (10 month, 1/1), ventricular tachycardia (12+/-4.9 yr, 6/6), postsurgical intraatrial reentrant tachycardia (15.6+/-4.1 yr, 2/3), twin node tachycardia (4 yr, 0/1), and His bundle ablation (9 yr, 1/1). The age of AVNRT was older than that of AVRT (p=0.002). Associated cardiac disease was detected in 17 patients, including 6 univentricular patients, and 3 Ebstein's anomaly patients. RFCA for multiple accessory pathways required longer fluoroscopic times than did the single accessory pathway (53.9+/-4.8 vs. 36.2+/-24.1 min; p=0.03), and was associated with a higher recurrence rate (3/9 vs. 3/53; p=0.03). Regardless of the presence or absence of cardiac diseases, the overall acute success rate was 97% without major complications, the recurrence rate was 8.2%, and the final success rate was 97%. This experience confirmed the efficacy and safety of RFCA in the management of tachycardia in children.

Epidemiologic picture of Kawasaki disease in Korea, 2000-2002.

BACKGROUND: The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for a 3 year period during 2000 to 2002. METHODS: An epidemiologic survey on Kawasaki disease was retrospectively performed. The questionnaire was sent to all 112 hospitals having pediatric residency programs, and obtained data were analyzed. RESULTS: The 9150 cases of Kawasaki disease from 92 hospitals which responded (response rate, 82.1%) included 5515 males and 3635 females (male : female ratio, 1.52:1). The incidence rate per 100,000 children <5 years old was 73.7 in 2000, and increased to 90.8 in 2001, and 95.5 in 2002 (average rate, 86.4). The monthly number of patients was slightly higher in May, June and July. Their mean age of onset, the proportion of sibling cases, and a rate of recurrent cases were 30.5 months, 0.17%, and 2.9%, respectively. Coronary arterial abnormalities occurred in 18.6% of cases including dilatations of 17.3% and aneurysms of 3.1%. CONCLUSION: The average annual incidence, 86.4/100 000 in children <5 years old is the second highest rate in the world.

Late occurrence of adenosine-sensitive focal junctional tachycardia in complex congenital heart disease.

BACKGROUND: Although supraventricular tachycardia in complex congenital heart disease (CHD) has been reported after surgical repair, its exact electrophysiologic identification has been limited to intraatrial reentrant tachycardia (IART). Moreover, junctional tachycardia (JT) has not previously been described as a cause of late postoperative arrhythmia. METHODS AND RESULTS: Since 1993, a total of 12 patients with congenital heart disease presented with paroxysmal focal JT. The patients with only typical immediate postoperative junctional ectopic tachycardia were excluded. Medical records, standard electrocardiography and Holter monitoring were reviewed. An intracardiac electrophysiologic (EP) study was performed in 11 patients. Ten patients were in post-Fontan status (5.7% of total Fontan survivors). Focal JT occurred more frequently in heterotaxy syndrome among the Fontan survivors (7/52 vs. 3/124; P < 0.05). The commonest anatomy of the atrioventricular (AV) junction was complete AV canal in 8 patients. EP characteristics of focal JT were as follows: (1) various tachycardia mechanisms were identified (increased automaticity or a triggered mechanism in 6/11, and focal reentry in 5/11, including one concealed nodofascicular pathway) (2) ventriculoatrial conduction during tachycardia was either dissociation (7/12) or variable (5/12) (3) All JTs were terminated by adenosine. Class III antiarrhythmic agent was effective in 5/6. His bundle ablation was performed in one Fontan patient, who already had pacemaker because of accompanying intractable IART and sinus node dysfunction. CONCLUSION: Focal JT may be a source of late term supraventricular tachycardia in patients with complex CHD. The tachycardia mechanism was either automatic/triggered or reentrant. In all patients, JT was effectively terminated by adenosine.

A case of congenital junctional ectopic tachycardia: diagnosis and successful radiofrequency catheter ablation in infancy.

It is difficult to make a definitive diagnosis of congenital junctional ectopic tachycardia (JET) in utero. We report a case in which congenial JET was suspected by fetal M-mode echocardiography. Fetal M-mode tracing of the atria and ventricle clearly showed a gradual acceleration of ventricular activity at the beginning of tachycardia, the warming-up sign of ectopic tachycardia, which was followed by simultaneous contractions of atrium and ventricle. This report also describes successful emergent radiofrequency catheter ablation of congenital JET in infancy with preservation of normal AV nodal conduction for this patient.

Twin AV node and induced supraventricular tachycardia in Fontan palliation patients.

INTRODUCTION: The coexistence of two distinct atrioventricular (AV) nodes has been described in congenital heart disease requiring Fontan type palliation. The purpose of this study was to evaluate the occurrence of twin AV node according to anatomical subgroups, and to determine its relation to tachycardia. METHODS: From 2001 to 2003, we performed an electrophysiologic (EP) study upon 52 consecutive patients who had undergone cardiac catheterization after Fontan completion. Atrial pacing was performed at three or more different atrial sites. RESULTS: In 10/52 patients, two different QRS complexes were recorded at different pacing sites, suggesting twin AV node (9/20 in right isomerism, 1/8 discordance AV connections, 0/24 other complex anomalies). AV reciprocating tachycardia (AVRT), presumably involving two AV nodes and a connecting sling, was induced in 6 of 10 patients who had twin AV node (4/6 used posterior AV node as an antegrade limb, 2/6 used an anterior AV node as an antegrade limb). Heterotaxy syndrome (P < 0.001) and complete AV septal defect (P = 0.002) were found to be risk factors for twin AV node. Junctional tachycardia (JT; HR > 150/min) with either VA dissociation (7/9) or second degree VA block (2/9) were induced by pacing or isoproterenol infusion in 9/52 patients. CONCLUSION: JT induction was associated with a twin AV node (P = 0.04), or a history of early postoperative junctional ectopic tachycardia (P = 0.02). A complicated AV node conduction system such as twin AV node was frequent in heterotaxy syndrome. Both AVRT and JT with VA block may be important causes of tachyarrhythmia in this patient group.

Elastic properties of the ascending aorta in young children after successful coarctoplasty in infancy.

BACKGROUND: Based on the hypothesis that vascular dysfunction in the ascending aorta can cause morbidity, we undertook this study on the elastic properties of ascending aorta and left ventricular (LV) function in young children who received coarctoplasty in early infancy. METHODS: Blood pressures (BP) in the right arm and ascending aortic internal diameters determined by M-mode ultrasound at rest and after exercise were measured in 25 patients (mean age, 6.4+/-3 years) and 22 control subjects (mean age, 5.8+/-2.4 years). Ascending aortic stiffness index and distensibility were calculated using BP measurements and ascending aortic internal diameters. In addition, LV parameters (systolic and diastolic function, mass index) were evaluated. RESULTS: Compared with control subjects, patients had increased stiffness index (at rest: 4.87+/-1.94 versus 3.57+/-1.19, P=0.021; after exercise: 4.33+/-1.91 versus 3.2+/-1.26, P=0.034) and decreased distensibility (at rest: 6.90+/-3.15 versus 8.72+/-2.77, P=0.02; after exercise: 5.69+/-2.39 versus 7.88+/-3.44 cm2 dyn(-1) 10(-6), P=0.023). BP and LV parameters showed no consistent differences between the two groups. In patients, distensibility was significantly correlated with systolic BP (at rest: P=0.008; after exercise: P=0.014) and pulse pressure (at rest: P=0.013; after exercise: P=0.001). CONCLUSIONS: This study suggests that vasculopathy of ascending aorta is possible in some young children despite early correction. However, long-term tracking study is needed to clarify the significance of the study.

The usefulness of surface electrocardiogram as a prognostic predictor in children with idiopathic dilated cardiomyopathy.

We investigated the interrelations between surface electrocardiographic changes and clinical outcomes in children with idiopathic dilated cardiomyopathy (DCMP). 33 patients (19 boys, 14 girls) were classified into two groups; group I (15) who were in poor clinical status or dead; and group II (18) who showed good clinical status. Group I had larger LV dimensions compared to group II (Gr I vs. Gr II; LVEDD, 52 +/-11 vs. 42+/-7 (mm); LVESD, 43+/-12 vs. 30+/-5 (mm); p<0.05). QRS duration was prolonged in Gr I compared to Gr II and normal (Gr I, 84+/-28; Gr II, 66+/-12; normal control, 67+/-9). The QRS duration was correlated with the dimensions of left ventricle (LV). Corrected QT and JT interval and dispersions of QT in the DCMP group showed a significant difference compared to the normal control, however there was no significant difference between Gr I and II. In conclusion, QRS duration was correlated with ventricular dimension and clinical outcome in children with idiopathic dilated cardiomyopathy. Irrespective of increased ventricular inhomogeneity, QT dispersion could not be used to predict long-term prognosis.