To Explore The Methods Of Calculating The Sinus Atrial Conduction Time Of Normal Children Of Different Age Stages By Transesophageal Atrial Pacing

Objective To explore the methods of calculating the reference range of sinus atrial conduction time (SACT)of normal children of different age stages by transesophageal atrial pacing, and to observe the effects of using different sinus cardiac length(SCL).Method A total of 168 normal children were divided into three groups,1～3 years,～7 years, and～14 years. All received constant atrial pacing to measure the SACT by transesophageal atrial pacing. The effects of using different intervals before or after pacing as the SCL were observed.Result Using the same interval as the SCL, the values of different sexes of children from the same age groups had no significant differences; while partial of the values of children of different age groups had significant differences, particularly between～14years and the other two groups. Through observing the values by using different intervals as the sinus cardiac length, the first sinus interval after pacing(A₃A₄) seemed to be the most proper one for calculating SACT, the average intervals after intubation before pacing(A₁A₁) came secondly. Using A₃A₄ as the SCL, the reference ranges of SACT of children of different age stages were as follows:～3 years, 77.00±14.376ms;～7 years, 83.81±29.792ms;～14 years, 97.80±29.864ms. Using A₁A₁ as the SCL, the reference ranges of SACT of children of different age stages were as fellows:～3 years, 86.50±25.172 ms;～7 years, 108.81±49.199ms;～14years, 124.78±44.567 ms.Conclusion 1. The SACT might prolong with age increasing, but the change developed slowly and gradually. 2. The SACTs of children of the same age had no sex differences; 3. Using different intervals as the sinus cardiac length did affect the values of the SACTs. The first sinus interval after pacing(A₃A₄) seemed to be the most proper one, and the average intervals after intubation before pacing(A₁A₁) came secondly.