Yu Yang, Wen Songnan, Ruan Yanfei, Liu Nian, Hu Shan, Duan Xiaoyu, Bai Rong
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China; Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Division of Cardiovascular Ultrasound, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.
Am J Cardiol. 2022 Apr 1;168:64-70. doi: 10.1016/j.amjcard.2021.12.016. Epub 2022 Jan 20.
Current knowledge on the dynamic changes of corrected QT (QTc) before, during, and after an atrial fibrillation (AF) episode is limited. It remains controversial which of the presently available formulas performs the best in calculating QTc during AF. This study was designed to explore whether an AF attack would affect QTc and to determine the performance of 6 available formulas in correcting QT before, during, and after AF. A total of 101 patients with Holter-documented paroxysmal AF were enrolled. QT interval before, during, and after AF was measured and corrected to heart rate (HR) by using Bazett, Fridericia, Framingham, Hodges, Dmitrienko, and RTHa formulas. In 40 patients, QTc under AF was compared with under sinus rhythm (SR) with identical HR. Although QT was significantly longer before AF and after AF compared with during AF; there was no difference in QTc between SR and AF with identical HR regardless of the formulas used. QTc calculated by the Framingham formula showed excellent homogeneity with a mean delta difference of -0.2 ± 41.6 ms (before AF vs AF) and -6.6 ± 35.4 ms (after AF vs AF), respectively. QTc corrected by the Bazett formula (before AF vs AF -38.7 ± 52.3 ms; after AF vs AF -42.6 ± 46.9 ms) yielded significant heterogeneity among the 3 time points. In conclusion, AF does not influence QTc. The Framingham formula accurately corrects QT without being affected by the AF episode. The Bazett formula significantly overestimated QTc during AF.
目前关于心房颤动（AF）发作前、发作期间及发作后校正QT（QTc）动态变化的知识有限。在AF发作期间计算QTc时，目前可用的公式中哪一个表现最佳仍存在争议。本研究旨在探讨AF发作是否会影响QTc，并确定6种可用公式在AF发作前、发作期间及发作后校正QT的性能。共纳入101例经动态心电图记录的阵发性AF患者。通过使用Bazett、Fridericia、Framingham、Hodges、Dmitrienko和RTHa公式测量AF发作前、发作期间及发作后的QT间期，并将其校正为心率（HR）。在40例患者中，比较了AF发作时与相同HR的窦性心律（SR）下的QTc。尽管与AF发作期间相比，AF发作前和发作后QT明显更长；但无论使用何种公式，相同HR下SR和AF之间的QTc无差异。由Framingham公式计算的QTc显示出极好的同质性，平均差值分别为-0.2±41.6ms（AF发作前与AF发作时）和-6.6±35.4ms（AF发作后与AF发作时）。由Bazett公式校正的QTc（AF发作前与AF发作时为-38.7±52.3ms；AF发作后与AF发作时为-42.6±46.9ms）在3个时间点之间产生了显著的异质性。总之，AF不影响QTc。Framingham公式能准确校正QT，不受AF发作的影响。Bazett公式在AF发作期间显著高估了QTc。
