Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formul...Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.展开更多
TRDP(Train Real Time Data)协议作为IEC61375-2-3标准指定的设备间各个系统进行通信的协议,在列车控制与信息服务网络(Train Control and Service Network,TCSN)得到了广泛的应用。由于TRDP协议是轨道交通私有协议,目前Wireshark软件对...TRDP(Train Real Time Data)协议作为IEC61375-2-3标准指定的设备间各个系统进行通信的协议,在列车控制与信息服务网络(Train Control and Service Network,TCSN)得到了广泛的应用。由于TRDP协议是轨道交通私有协议,目前Wireshark软件对TRDP协议析解析尚不支持。通过对TRDP协议进行分析,利用Qt读取Excel通信协议文件,自动化生成适用于TRDP协议解析的Lua代码插件,实现在Wireshark中对TRDP协议的识别以及对报文头首部、数据区协议内容解析,同时实现了对TRDP报文的丢包检测、周期分析功能,可以广泛应用于子系统通信之间数据一致性测试及现场列车通信调试。展开更多
基金This study was reviewed and approved by the New York-Presbyterian Brooklyn Methodist Hospital Institutional Review Committee.The study follows the guidelines outlined in the Declaration of Helsinki.
文摘Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.
文摘TRDP(Train Real Time Data)协议作为IEC61375-2-3标准指定的设备间各个系统进行通信的协议,在列车控制与信息服务网络(Train Control and Service Network,TCSN)得到了广泛的应用。由于TRDP协议是轨道交通私有协议,目前Wireshark软件对TRDP协议析解析尚不支持。通过对TRDP协议进行分析,利用Qt读取Excel通信协议文件,自动化生成适用于TRDP协议解析的Lua代码插件,实现在Wireshark中对TRDP协议的识别以及对报文头首部、数据区协议内容解析,同时实现了对TRDP报文的丢包检测、周期分析功能,可以广泛应用于子系统通信之间数据一致性测试及现场列车通信调试。
