The QRS time limit is 106ms, in the case of adults most people are between 60~100ms, with a maximum of 110ms being normal. In children, it is usually between 40 and 80ms.
QRS is a group of waves formed by the depolarization of the right and left ventricles. During an ECG examination, a QRS appears with each heartbeat, which represents a contraction of the heart.
There is a difference between adults and children in the normal range of the QRS time frame. When the QRS time frame is greater than 110 ms (90 ms in children), it is called QRS widening. In adults, this is higher than the normal range, but not QRS widening, so mild ventricular hypertrophy may be present.
However, in the case of children, the QRS time limit of 106ms is a QRS widening condition, which may be caused by intraventricular block, ventricular ectopic beats, cardiac hypertrophy, etc. A cardiac ultrasound is usually needed to make a clear diagnosis.
The results of ECG need to be analyzed together, and sometimes a single value cannot be used as the basis for diagnosis. Usually, it needs to be combined with the patient’s related examination results and clinical symptoms for diagnosis.