Nakaji Gen, Fujiwara Masahiko, Fukata Mitsuhiro, Yasuda Shioto, Odashiro Keita, Maruyama Toru, Akashi Koichi
Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
J Electrocardiol. 2010 May-Jun;43(3):261-3. doi: 10.1016/j.jelectrocard.2009.12.005. Epub 2010 Jan 18.
Delay of QT interval adaptation to sudden heart rate change causes hysteresis in dynamic QT-RR relationship. We analyzed QT-RR plotting during and after exercise in a patient with genetically identified type 2 long QT syndrome before and after starting oral propranolol. Blunted QT shortening by exercise and augmented postexercise QT prolongation resulted in an open-loop, clockwise QT-RR hysteresis immediately before the onset of torsades de pointes before propranolol. However, this hysteresis was eliminated by propranolol. QT-RR analysis provided insight into the mechanisms of the onset of torsades de pointes at least in this case of type 2 long QT syndrome.
QT间期对心率突然变化的适应性延迟会导致动态QT-RR关系中的滞后现象。我们分析了一名经基因鉴定为2型长QT综合征的患者在开始口服普萘洛尔前后运动期间及运动后的QT-RR绘图情况。运动时QT缩短减弱以及运动后QT延长加剧，导致在普萘洛尔治疗前发生尖端扭转型室速发作前立即出现开环、顺时针方向的QT-RR滞后现象。然而，这种滞后现象被普萘洛尔消除了。至少在这种2型长QT综合征病例中，QT-RR分析为尖端扭转型室速的发作机制提供了见解。
