Yukiharu Kono

Face immersion in cold water induces prolongation of the QT interval and T-wave changes in children with nonfamilial long QT syndrome

We investigated the relation between heart rate and the QT interval using face immersion in cold water in children with long QT syndrome (LQTS) without a family history of this condition, and in control children. The face immersion test revealed that all children with high probability of LQTS had a significantly longer QT interval than control children during face immersion, and that the test could induce T-wave alternans or a notched T-wave in all children with a high probability of LQTS.

Effect of total adipose weight and systemic hypertension on left ventricular mass in children

To investigate the effect of obesity and hypertension on left ventricular (LV) mass in children, we performed echocardiography and measured the height, weight, and blood pressure of 267 healthy children (145 boys and 122 girls) aged 12 years. The percentage of body fat was estimated using bioelectric impedance to derive the total adipose weight and lean body weight. End-diastolic measurements of LV parameters were obtained from M-mode echocardiograms. The LV mass was calculated by using the formula of Devereux et al. A strong positive correlation was demonstrated between non-normalized LV mass and height or other measures of body size. Systolic blood pressure was weakly correlated with non-normalized LV mass in boys. The impact of height on LV mass differed between boys and girls. Thus, different allometric formulas to normalize the LV mass for height were determined, using the height to the 3.1 and 1.9 powers for boys and girls, respectively. Regression analysis revealed that only total adipose weight affected the normalized LV mass, and that the effect of total adipose weight was greater in girls than in boys. The obese children had a significantly greater normalized LV mass than the nonobese children. The increase in the LV mass due to obesity appeared to be eccentric, because of the lack of an association between the indices of obesity and relative wall thickness. Our data indicate that appropriate normalization of LV mass is necessary for each study population, and that LV hypertrophy due to obesity begins in childhood.

Effect of obesity on echocardiographic parameters in children

We studied the effect of obesity on echocardiographic parameters in Japanese children. The subjects were 341 children: 106 first graders (age 6 years), 166 seventh graders (age 12 years), and 69 tenth graders (age 15 years). They were assigned to six groups according to school grade and sex. Echocardiographic parameters included thickness of the interventricular septum and of the posterior wall, end diastolic left ventricular internal dimension, and left ventricular mass. Left ventricular parameters were normalized for height, and for height to the power of 2.7. The obesity index as well as the body mass index were used to estimate obesity, because the obesity index is frequently used in Japan. There were significant correlations between the indices of obesity and left ventricular internal dimension or left ventricular mass in each group. The obesity index was more strongly correlated than the body mass index with posterior wall thickness and left ventricular internal dimension. For normalization of left ventricular parameters, correction for height was better for the first graders, whereas correction for height to the power of 2.7 was better for seventh and tenth graders. The most important finding was that the effect of obesity on left ventricular parameters was evident at 6 years of age.

Selective IgA deficiency complicated by Kawasaki syndrome

© 2008 Japan Pediatric Society Selective absence of serum IgA is the most common defect among primary immunodefi ciency diseases, with rates ranging from 1/333 to 1/16 000 persons among different races. 1 Serum antibodies to IgA are reported in as many as 44% of patients with selective IgA defi ciency. 1 In these patients, administration of blood products containing IgA may cause severe or fatal anaphylactic reactions. Therefore, administration of blood products is usually considered a contraindication for patients with selective IgA defi ciency. A 2-year-old boy with selective IgA defi ciency complicated by Kawasaki syndrome (KS) was admitted to Izumi City Hospital. For patients with KS, administration of a high dosage of i.v. immunoglobulin (IVIG) and the oral administration of aspirin are recommended. 2,3 The present patient, however, needed treating without the use of IVIG. We successfully treated him using i.v. administration of methylprednisolone instead of IVIG. This is the fi rst report of selective IgA defi ciency complicated by KS.

Estimation of myocardial damage in Kawasaki disease using antimyosin antibody

In a retrospective study, 121 children with Kawasaki disease (KD) were investigated to determine (i) the incidence of myocardial damage using the antimyosin antibody (AMA) titer; (ii) the differences in the electrocardiograms between the AMA‐positive and ‐negative patients; and (iii) the effect of treatment with intravenous gamma globulin (IVGG) on the AMA. Comparisons were made with 117 normal children (controls).

Risk factors for persistence of pulmonary arterial branch stenosis in neonates and young infants

Background : Pulmonary arterial branch stenosis (PBS) in neonates is considered to be transient. However, PBS has been found not only in neonates, but also in young infants. Among these patients, we encountered several patients whose PBS was still present after the age of 1 year.

A Simple Method for Evaluating Abnormal Lengthening of the QT Interval During the Face Immersion Test

The slope of the relation between the unadjusted QT interval and heart rate during the face immersion test has been reported to be useful as an index for predicting an abnormal lengthening of the QT interval for children with nonfamilial long QT syndrome. Our goals were to determine whether we can replace the slope of the QT/heart rate relation calculated from all data with that calculated from fewer data and to determine whether we can replace the slope with the corrected QT value by heart rate (QTc value) at the minimum heart rate. We studied 19 children with a prolonged QT interval and 54 control children by using statistical analysis. The slope calculated from the selected data points (at least four) was in agreement with the slope calculated from all data, and the relationship between the slope and the QTc value at the minimum heart rate showed a high correlation. It was determined that we can replace the slope calculated from all data with that calculated from at least four data points and replace the slope with the QTc value at the minimum heart rate as an index for predicting an abnormal lengthening of the QT interval.