Tereshchenko Larisa G, Fetics Barry J, Berger Ronald D
The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21287, USA.
J Electrocardiol. 2009 Nov-Dec;42(6):505-10. doi: 10.1016/j.jelectrocard.2009.07.011. Epub 2009 Aug 22.
We previously showed that increased intracardiac repolarization lability predicts life-threatening ventricular arrhythmias in patients with structural heart disease. Patients with structural heart disease frequently take antiarrhythmic drugs (AADs), which directly affect repolarization. The effect of AADs on the predictive value of repolarization lability is unknown. We hypothesized that increased intracardiac beat-to-beat QT variability predicts sustained ventricular tachyarrhythmias in structural heart disease patients on class III AADs. Intracardiac electrograms and surface electrocardiogram were simultaneously recorded at rest for 5 minutes in 500 patients (mean +/- SD age, 61 +/- 14 years; 368 male [74%]) with implanted implantable cardioverter-defibrillator for primary (295 patients, or 79%) or secondary prevention of sudden cardiac death. Mean (SD) follow-up currently reached 24.8 (11.7) months. Intracardiac QT variability index was an independent predictor of ventricular tachycardia/ventricular fibrillation events and fast ventricular arrhythmias with cycle length of 240 ms or less in the multivariate Cox model. Intracardiac QT variability was higher in patients on class III AADs than in those not taking these drugs. Increased intracardiac QT variability after adjustment for class III AADs use carried independent risk of life-threatening ventricular tachyarrhythmias.
我们之前的研究表明，心脏复极易变性增加可预测结构性心脏病患者发生危及生命的室性心律失常。结构性心脏病患者常服用直接影响复极的抗心律失常药物（AADs）。AADs对复极易变性预测价值的影响尚不清楚。我们假设，心脏逐搏QT变异性增加可预测服用Ⅲ类AADs的结构性心脏病患者发生持续性室性快速心律失常。对500例（平均±标准差年龄，61±14岁；368例男性[74%]）因心脏性猝死的一级预防（295例患者，占79%）或二级预防而植入植入式心脏复律除颤器的患者，在静息状态下同时记录5分钟的心内心电图和体表心电图。目前平均（标准差）随访时间达24.8（11.7）个月。在多变量Cox模型中，心内QT变异性指数是室性心动过速/心室颤动事件以及周期长度为240 ms或更短的快速室性心律失常的独立预测指标。服用Ⅲ类AADs的患者心内QT变异性高于未服用这些药物的患者。在对Ⅲ类AADs的使用进行校正后，心内QT变异性增加具有发生危及生命的室性快速心律失常的独立风险。
