Howley Lisa W, DI Maria Michael, Bailey Amy, Schaffer Michael S
Section of Pediatric Cardiology University of Colorado, Denver, The Children's Hospital, Aurora, Colorado 80045, USA.
Pacing Clin Electrophysiol. 2010 Mar;33(3):377-9. doi: 10.1111/j.1540-8159.2009.02550.x. Epub 2009 Sep 30.
A female infant presented with bradycardia and an electrocardiogram demonstrating 2:1 atrioventricular depolarization, a prolonged QT interval, and T wave alternans. After propranolol therapy was initiated, a lidocaine challenge was performed with progressive shortening of the QT interval. This positive lidocaine challenge prompted clinical suspicion of long QT syndrome type 3 (LQT3) and early initiation of mexiletine therapy. Subsequent genetic testing confirmed the infant's diagnosis of LQT3.
一名女婴出现心动过缓，心电图显示2:1房室去极化、QT间期延长和T波交替。在开始使用普萘洛尔治疗后，进行了利多卡因激发试验，结果QT间期逐渐缩短。利多卡因激发试验呈阳性，这引起了临床对3型长QT综合征（LQT3）的怀疑，并促使早期开始使用美西律治疗。随后的基因检测证实了该婴儿LQT3的诊断。
