Criteria for Evaluating Abnormal Signal-Averaged Electrocardiogram in Children Classified by Age, Body Surface Area and Height

We evaluated criteria for the diagnosis of ventricular abnormal signal-averaged electrocardiogram (SAE) in 205 healthy children classified by age, body surface area and height. The children were classified by age into 4 groups: under 3 months old, 3 months old or more but less than 1 year old, 1 year old or more but less than 12 year old and 12 year old or more. They were also divided by body surface area into 4 groups: under 0.3 m2, 0.3 m2 or more but less than 0.5 m2, 0.5 m2 or more but less than 1.2 m2, and 1.2 m2 or more. In terms of height, they were classified into 4 groups: under 60 cm, 60 cm or more but less than 80 cm, 80 cm or more but less than 140 cm, and 140 cm or more. The boundary points in these 3 classifications were statistically consistent. Criteria for abnormal SAE in children classified according to age were filtered QRS duration (f-QRSd) >95 msec, root mean square (RMS) 25 msec in those under 3 months old; f-QRSd >110 msec, RMS 30msec in those 3 months or more but less than 1 year old; f-QRSd >115 msec, RMS 30msec in those 1 year old or more but less than 12 year old; and f-QRSd >125 msec, RMS 30 msec in those 12 year old or more. The criteria for evaluating abnormal SAE were similar regardless of whether children were classified by age, body surface area or height. Using these values as criteria, the 205 children were evaluated for the presence of abnormal SAE. All of the children were negative for abnormal SAE using these criteria according to age, body surface area or height. In evaluating abnormal SAE in children, it is useful to classify children by age, body surface area and height and to identify the criteria in each group. In this study, the criteria based on height and age were particularly useful, since these are more convenient than body surface area. (Jpn Circ J 1996; 60: 228 - 238)