De Oliveira Neto Nestor R, De Oliveira William Santos, Campos Pinto Guilherme D, De Oliveira Eric Santos R, Da Silveira Barros Maria das Neves D
Cardiology, Hospital Universitário Onofre Lopes, Natal, BRA.
Cardiology, University of Pernambuco (UPE), Recife, BRA.
Cureus. 2020 Dec 17;12(12):e12122. doi: 10.7759/cureus.12122.
Objective The various formulae used for QT correction by heart rate (HR) require the execution of operations with the aid of calculators or applications. This study aimed to evaluate the performance of a simple rule for QTc estimation, comparing the measurements obtained with those provided by the commonly used equations of Bazett, Fridericia, Framingham, and Hodges. Methods We used the database of a previous observational study, which analyzed patients prospectively with acute pulmonary edema admitted in an emergency service. One hundred four patients were included for QTc assessment, of whom 86 patients underwent two ECG: one ECG <24h and other >24h after admission. Thus, a total of 190 ECGs were analyzed by two observers that manually measured QT and HR. QTc was obtained using the known formulae and the proposed equations: QTc = QT+2 (FC-60) for HR ≤ 90 bpm and QTc=QT+2(FC-60)-10 for HR>90 bpm. Results Bland-Altman plots show good agreement between the simple rule and Hodges equation, with a mean difference of -3,4, SD of 4.96 and 95% limits of agreement from -9,9 to 3.2. There was not a good agreement between the simple method and the other formulae. Conclusion The proposed method has good agreement with the measures of QTc by the equation of Hodges in the HR range of 40 to 130bpm in acutely ill patients. Our method may be a plausible option for quick QT correction in these subjects.
目的 用于心率（HR）校正QT的各种公式需要借助计算器或应用程序来执行运算。本研究旨在评估一种简单的QTc估算规则的性能，将其获得的测量值与常用的Bazett、Fridericia、Framingham和Hodges方程提供的测量值进行比较。方法 我们使用了先前一项观察性研究的数据库，该研究对在急诊服务中前瞻性分析的急性肺水肿患者进行了分析。纳入104例患者进行QTc评估，其中86例患者接受了两次心电图检查：一次在入院后<24小时，另一次在入院后>24小时。因此，两名观察者对总共190份心电图进行了分析，手动测量了QT和HR。使用已知公式和提议的方程获得QTc：对于HR≤90次/分钟，QTc = QT + 2（FC - 60）；对于HR>90次/分钟，QTc = QT + 2（FC - 60）- 10。结果 Bland-Altman图显示简单规则与Hodges方程之间具有良好的一致性，平均差异为-3.4，标准差为4.96，一致性界限为-9.9至3.2。简单方法与其他公式之间没有良好的一致性。结论 在所提议的方法与急性病患者心率范围在40至130次/分钟时Hodges方程测得的QTc值之间具有良好的一致性。我们的方法可能是这些受试者快速QT校正的一个合理选择。
