C. C. Laura Meng

Characteristics of Kawasaki disease in infants younger than six months of age.

Background: Kawasaki disease is the leading cause of acquired heart disease in childhood. However, there are only a few reports in infants younger than 6 months. The objective of this study is to investigate the clinical and laboratory characteristics of Kawasaki disease in infants younger than 6 months. Methods: From 1994 to 2003, 120 patients with Kawasaki disease diagnosed at our institution were included. Group 1 consisted of 20 (17%) patients younger than 6 months, and group 2 consisted of 100 (83%) patients older than 6 months. Clinical manifestations, laboratory results, echocardiographic findings, treatment and outcome were compared between these 2 groups. Results: Clinical manifestations (hydrops of gallbladder: 0% versus 16%, P < 0.001) and laboratory results (white blood cell count 21,740 ± 11,706 versus 11,830 ± 4390/mm3, P < 0.001; hemoglobin 9.98 ± 1.25 versus 10.8 ± 1.37 g/dL, P = 0.015; platelet 483 ± 393 versus 355 ± 138 × 1000/mm3, P = 0.011; triglyceride 138 ± 77.5 versus 107 ± 17 mg/dL, P < 0.001) were different between patients with Kawasaki disease younger and older than 6 months, respectively. Younger infants were more likely to have incomplete presentation (35% versus 12%, P = 0.025), coronary involvement (65% versus 19%, P < 0.001), late intravenous immunoglobulin treatment and relatively poor outcome. Conclusions: Infants younger than 6 months with prolonged unexplained febrile illnesses should be suspected as having Kawasaki disease, despite the incomplete clinical presentation. Because early diagnosis and timely treatment are difficult in younger infants with Kawasaki disease because of delayed and incomplete clinical presentations, echocardiogram becomes an important implement for diagnosis. Early intravenous immunoglobulin treatment is required in view of the highest risk of coronary involvement in them.

The Clinical Manifestations and Risk Factors of a Delayed Diagnosis of Kawasaki Disease

Background: Kawasaki disease (KD) is an acute febrile vasculitis and may cause coronary artery abnormalities. Due to the higher incidence in Asian countries, most pediatricians in Taiwan are familiar with KD. However, there are still some patients being diagnosed 10 days after the onset of the illness and not receiving a highly effective therapy. In this study, we analyzed the risk factors and clinical manifestations of patients with a delayed diagnosis of KD. Methods: A retrospective review was made of the medical records of the patients diagnosed with KD at our institution between January 1996 and December 2005. The patients were divided into 2 groups: early‐diagnosis group (EDG: diagnosis was made within 10 days after the onset of the fever) and delayed‐diagnosis group (DDG: diagnosis was made 10 days after the onset of the fever). Results: Fourteen of a total of 78 children (17.9%) were grouped into the DDG group, and 64 into the EDG group. There were no statistical differences between the 2 groups in terms of age, gender, number of antibiotics used, day of the first medical visit, total days of skin rash, conjunctivitis, mucosa changes, lymphadenopathy or laboratory examinations except for the higher white blood cell count and serum immunoglobulin G level in the DDG group. The patients in the EDG group had a clustered onset of symptoms as compared to the DDG group with a dispersed and late onset of symptoms. There was a higher risk of coronary artery abnormalities in the DDG group than the EDG group (42.9% vs. 14.1%; p = 0.036), and in the patients with KD who were younger than 1 year (29.0% vs. 12.7%; p = 0.043). Conclusion: Patients with delayed diagnosis of KD were associated with higher risk of developing coronary arterial lesions. It is necessary to develop a diagnostic test for KD and provide more education to health care providers for early recognition of KD.

Transcatheter implantation of intravascular stents for postoperative residual stenosis of peripheral pulmonary artery stenosis.

This is a prospective study of transcatheter implantation of 11 intravascular stents in 7 patients with status/post (S/P) surgical correction of major cardiovascular lesions. The safety and efficacy of balloon-expandable stents for treatment of peripheral pulmonary artery stenosis (PPAS) is evaluated and analyzed. Although the transcatheter implantation of intravascular stents has been reported as a possible treatment for stenotic peripheral pulmonary arteries, the results of intermediate follow-up studies on patients with S/P surgical correction for residual PPAS need to be evaluated. From June 1998 to December 2001, a total of 15 patients with PPAS having S/P surgery for major cardiovascular lesions were enrolled in this study. Eight of them had redo surgery after complete evaluation and the other 7 patients who might be at higher risk of mortality or morbidity from redo surgery, underwent transcatheter implantation of stents to dilate significant PPAS. Tetralogy of Fallot, S/P total correction, was done in 6 and transposition of great vessels, S/P Jatene operation, was done in 1. There were 10 stents (P 308 Palmaz stent ×8 and Intrastent™ ×2) implantation for 10 sites of the stenotic PPAS in these 7 patients, who were aged from 3.6 to 17.3 (10.1 ±5.6) years and had body weights ranging from 17 to 72.5 (37.1 ±23.0) kg. The narrowest diameter of the stenotic peripheral pulmonary arteries and pressure gradients across the stenosis were measured before and after implantation of stents. A follow-up catheterization and pulmonary angiography was performed 1 year later to evaluate the intermediate efficacy of stents implantation. All the stenotic peripheral pulmonary arteries of these 7 patients had a significant reduction of pressure gradients immediately after the procedure. The narrowest mean diameter of pulmonary arteries increased from 6.7 ±3.4 to 11.3 ±3.0 mm (p<0.001), and the mean pressure gradient dropped from 31 ±9.9 to 11.4 ±4.6 mm Hg (p<0.001). The follow-up catheterization 1 year later revealed a persistent effect in all but 1 patient. Only a young male presented with a recurrent stenosis with a pressure gradient of ≥20 mm Hg, which was relieved by redilation with implantation of another stent. There was no immediate or intermediate complication. Transcatheter stent implantation for treatment of a significant residual PPAS after surgical correction of complicated congenital heart disease is a safe and effective procedure. Since children are growing with age, a long-term follow-up study to evaluate the effects and possible problems of stent implantation is mandatory.

The specific characteristics in children with obstructive sleep apnea and cor pulmonale.

Background. The prevalence of obstructive sleep apnea (OSA) in the pediatric population is currently estimated at 1-2% of all children. The purpose of this study was to investigate the clinical and hemodynamic characteristics in pediatric patients with cor pulmonale and OSA. Methods. Thirty children with the diagnosis of OSA were included. These patients consisted of 26 male and 4 female children with a mean age of 7 ± 4 years old. Five of those children were found to be associated with cor pulmonale, and 25 had OSA but without cor pulmonale. Results. The arousal index was much higher in children with OSA and cor pulmonale. The children with OSA and cor pulmonale had much lower mean and minimal oxygen saturation and a higher incidence of bradycardia events. All 5 patients with OSA and cor pulmonale underwent an adenotonsillectomy, and the pulmonary arterial pressure dropped significantly after the surgery. Conclusion. This study demonstrated that the OSA pediatric patients with cor pulmonale had the different clinical manifestations and hemodynamic characteristics from those without cor pulmonale. The adenotonsillectomy had excellent results in both the OSA pediatric patients with and without cor pulmonale.

Multifocal atrial tachycardia in 2 children.

The incidence of multifocal atrial tachycardia (MAT) is very low and accounts for less than 1% of supraventricular tachycardia in infants and children. In this report, the clinical characteristics, medical treatment and outcome of MAT in 2 children are described. The first patient presented with tachycardia and respiratory failure since the day after birth. First, he received amiodarone, propranolol, and digoxin and then amiodarone alone. The heart rhythm converted to sinus rhythm 2 weeks after hospitalization. Although nonsustained MAT was occasionally observed when the infant suffered from pulmonary infection, the frequency of recurrent MAT decreased as the infant grew up. The second patient was a 5-year-old girl. She had congenital heart disease with double outlets of right ventricle (DORV), patent ductus arteriosus, coarctation of aorta, and ventricular and atrial septal defects. She underwent total correction at the age of 4 years. MAT was noted 3 months after the operation with the presentation of congestive heart failure. The heart rate slowed down and returned to normal sinus rhythm within several hours after amiodarone use. The symptoms and signs of congestive heart failure also disappeared. The patient took amiodarone regularly, and no tachycardia was detected during the follow-up period. MAT is considered to be a relatively benign arrhythmia with likely good outcome if there is no severe underlying illness. It can be well controlled under appropriate drugs, and a long period of follow-up is suggested. If pharmacologic intervention is required, we suggest that amiodarone may be an excellent choice.

Comparison of the one-and-a-half-year results of closure of patent ductus arteriosus by transcatheter coils placement with surgical ligation.

Patent ductus arteriosus (PDA) is a common type of congenital cardiovascular lesion. It usually needs surgical ligation in a full-term baby after 1 year of age. Transcatheter implantation of coils was introduced for the closure of small- to moderate-sized PDA in 1992. From November 1995 to November 1998, the authors closed the PDA in 153 patients by transcatheter implantation of coils and by surgical ligation in 10 patients. One hundred fourteen of them were studied for more than 1½ years. The regular follow- up studies, including physical examination; electrocardiography; and pulsed, continuous- wave, and color Doppler flow mapping, were performed on day one and day 2, and 1 week, 1 month, 3 months, 6 months, and 1 year after the procedure. The results of the closure of PDA by surgical ligation or coil placement were compared and analyzed in all the patients.

Percutaneous Balloon Valvuloplasty in Severe Pulmonary Valvular Stenosis

Percutaneous balloon pulmonary valvuloplasty (PBPV) was achieved successfully in 20 of 22 patients with severe pulmonary valvular stenosis, aged two days to ten years (median four years and two months). The diameters of the balloon for PBPV were 88-125% (mean ±SD=109.5 ±10.0%) of the pulmonary valve annulus. PBPV failed in 2 patients because of the inability of the cardiac catheters to cross the stenotic valve. A significant reduction of right ventricle-pulmonary artery (RV-PA) pressure gradient occurred in all 20 patients (mean ±SD=72.1 ±10.3%). The mean RV-PA pressure gradient was reduced from 93.2 ±33.1 to 26.3 ± 15.6 mmHg (P < 0.0001) and the mean right ventricular peak systolic pressure fell from 117.2 ±32.4 to 51.6 ±17.3 mmHg (P < 0.0001). Five (25%) of 20 patients had an infundibular gradient before PBPV. Two (10%) developed a new infundibular stenosis immediately after PBPV. Four (20%) presented with cyanosis, which disappeared after the successful PBPV. Two patients (10%) who showed a residual RV- PA pressure gradient of more than 40 mmHg had a significant infundibular obstruction initially. Two patients underwent recatheterization fifteen months after PBPV owing to a significant residual RV-PA pressure gradient and had no reductions in right ventricular pressure and RV-PA pressure gradient, but resolution of infundibular obstruction was noted in both. Repeat PBPV was successfully performed on these 2 patients. No significant complications were noted in any patient. It is concluded that PBPV with a balloon diameter of 88-125% of the pulmonary valve annulus is the first choice to treat a patient with severe pulmonary valvular stenosis, even in early infancy.

Assessment of Left Ventricular Dysfunction in Children Undergoing Chemotherapy

Background: In Taiwan, children with malignancies are treated under the protocols of the Taiwan Pediatric Oncology Group (TPOG). The purpose of this study was to determine the change in left ventricular (LV) function in pediatric patients undergoing chemotherapy. Methods: A total of 19 pediatric patients (mean age, 12.5 ± 4.6 years; 11 males, 8 females) were enrolled. We divided the patients into 2 groups: (1) osteogenic sarcoma (OGS) group (n = 12; Group I); and (2) non‐osteogenic sarcoma (non‐OGS) group (n = 7; Group II). The accumulated dosages of anthracycline in Group I and II patients were 144.3 ± 56.4 mg/M2 and 131.7 ± 105.5 mg/M2 (p= 0.735), respectively. The children received echocardiography to investigate the parameters of LV systolic function, LV diastolic function, and myocardial performance index (MPI) after the entire chemotherapy course. Results: Higher E/A ratio (1.71 ± 0.37), shorter isovolumic relaxation time (IRT, 42 ± 19.14 ms), and shorter deceleration time (DT, 140.3 ± 40.6 ms) were demonstrated in these patients. There was no statistically significant difference in the E/A ratio and DT between the 2 groups. Group I children were older (14.4 ± 3.7 vs. 9.3 ± 4.5 years; p = 0.015) and had lower MPI (0.20 ± 0.02 vs. 0.28 ± 0.07; p = 0.031) than Group II children. Conclusion: The children treated with chemotherapy using the TPOG protocol had a shorter IRT, higher E/A ratio and shorter DT. No significant evidence of anthracycline‐related cardiotoxicity was found in any of the children in this study undergoing chemotherapy with the TPOG protocol.

Myocaridal Scintigraphy with 99mTc-Sestamibi in Patients with Kawasaki Disease

To verify the usefulness of a semi-invasive assessment of myocardial perfusion, rest and dipyridamole 99mTc-Sestamibi scintigraphy were performed on 62 patients (19 females and 43 males) with Kawasaki disease. Their ages at the onset of Kawasaki disease ranged from 3 months to 10 years. The nuclear medicine study was performed at the age of 3.5 months to 18 years (6.5±5.3 years); they were 0.5 month to 17 years after the onset of illness. Among them, coronary arterial dilatation had been detected by two-dimensional echocardiography in 9 patients. Four of them were also demonstrated by cardiac catheterization. Seven of them with coronary arterial lesions showed 99mTc-Sestamibi scintigraphic abnormalities. Perfusion defects were also detected in 18 of 53 patients (false positive rate 34.0%) with normal coronary arteries on echocardiography or cineangiography. The sensitivity, specificity, positive and negative predictive value of 99mTc-Sestamibi scintigraphy for detection of myocardial dysfunction which may indicating coronary arterial lesions were 77.8% (7/9), 66.0% (35/53), 28% (7/25) and 94.6% (35/37). The higher negative predictive value (94.6%) and sensitivity (77.8%) suggest that rest and dipyridamole 99mTc-Sestamibi scintigraphy is an useful and semi-invasive method for detecting coronary arterial insufficiency and long-term follow-up study of patients with Kawasaki disease.

Detachment of Balloon in An Infant: A Rare Complication of Balloon Pulmonary Valvuloplasty

A 3-month-old infant with severe tetralogy of Fallot underwent percutaneous balloon valvuloplasty. After the successful dilatation, the balloon could not be deflated completely and the partial deflated balloon was totally peeled off from the catheter at the junction of inferior vena cava and right common iliac vein when we attempted to move it out. The skin of the balloon was successfully retrieved with a snared guidewire without sequel.