Department of Medical Physiology University Medical Center Utrecht Utrecht The Netherlands.
Department of Cardiology University Medical Center Utrecht Utrecht The Netherlands.
J Am Heart Assoc. 2020 Dec;9(23):e018133. doi: 10.1161/JAHA.120.018133. Epub 2020 Nov 20.
Background Short-term variability of the QT interval (STV) has been proposed as a novel electrophysiological marker for the prediction of imminent ventricular arrhythmias in animal models. Our aim is to study whether STV can predict imminent ventricular arrhythmias in patients. Methods and Results In 2331 patients with primary prophylactic implantable cardioverter defibrillators, 24-hour ECG Holter recordings were obtained as part of the EU-CERT-ICD (European Comparative Effectiveness Research to Assess the Use of Primary Prophylactic Implantable Cardioverter Defibrillators) study. ECG Holter recordings showing ventricular arrhythmias of >4 consecutive complexes were selected for the arrhythmic groups (n=170), whereas a control group was randomly selected from the remaining Holter recordings (n=37). STV was determined from 31 beats with fiducial segment averaging and calculated as [Formula: see text], where represents the QT interval. STV was determined before the ventricular arrhythmia or 8:00 am in the control group and between 1:30 and 4:30 am as baseline. STV at baseline was 0.84±0.47 ms and increased to 1.18±0.74 ms (<0.05) before the ventricular arrhythmia, whereas the STV in the control group remained unchanged. The arrhythmic patients were divided into three groups based on the severity of the arrhythmia: (1) nonsustained ventricular arrhythmia (n=32), (2) nonsustained ventricular tachycardia (n=134), (3) sustained ventricular tachycardia (n=4). STV increased before nonsustained ventricular arrhythmia, nonsustained ventricular tachycardia, and sustained ventricular tachycardia from 0.80±0.43 ms to 1.18±0.78 ms (<0.05), from 0.90±0.49 ms to 1.14±0.70 ms (<0.05), and from 1.05±0.22 ms to 2.33±1.25 ms (<0.05). This rise in STV was significantly higher in sustained ventricular tachycardia compared with nonsustained ventricular arrhythmia (+1.28±1.05 ms versus +0.24±0.57 ms [<0.05]) and compared with nonsustained ventricular arrhythmia (+0.34±0.87 ms [<0.05]). Conclusions STV increases before imminent ventricular arrhythmias in patients, and the extent of the increase is associated with the severity of the ventricular arrhythmia.
QT 间期的短期变异性（STV）已被提出作为一种新的电生理标志物，用于预测动物模型中即将发生的室性心律失常。我们的目的是研究 STV 是否可以预测患者即将发生的室性心律失常。
在 2331 名接受原发性预防性植入式心脏复律除颤器的患者中，作为欧盟-CERT-ICD（评估原发性预防性植入式心脏复律除颤器使用的欧洲比较有效性研究）研究的一部分，获得了 24 小时心电图 Holter 记录。选择显示 >4 个连续复杂的室性心律失常的 ECG Holter 记录用于心律失常组（n=170），而对照组则从其余的 Holter 记录中随机选择（n=37）。使用 31 个带有基准段平均的心动图来确定 STV，并计算为 [公式：见文本]，其中 代表 QT 间期。在室性心律失常之前或对照组的上午 8 点确定 STV，而在基线时则在下午 1:30 到 4:30 之间确定。在室性心律失常之前，基线时的 STV 为 0.84±0.47 ms，并增加到 1.18±0.74 ms（<0.05），而对照组的 STV 保持不变。根据心律失常的严重程度将心律失常患者分为三组：（1）非持续室性心律失常（n=32），（2）非持续室性心动过速（n=134），（3）持续性室性心动过速（n=4）。非持续室性心律失常、非持续室性心动过速和持续性室性心动过速前的 STV 从 0.80±0.43 ms 增加到 1.18±0.78 ms（<0.05），从 0.90±0.49 ms 增加到 1.14±0.70 ms（<0.05），从 1.05±0.22 ms 增加到 2.33±1.25 ms（<0.05）。与非持续室性心律失常（+1.28±1.05 ms 比+0.24±0.57 ms [<0.05]）和非持续室性心律失常（+0.34±0.87 ms [<0.05]）相比，持续性室性心动过速中的 STV 升高幅度明显更高。
STV 在患者即将发生室性心律失常之前增加，增加的程度与室性心律失常的严重程度相关。
