■评估在接受睡眠研究的慢性阻塞性肺疾病(COPD)患者中,目的设计的QTc评分算法与既定的手动评分算法的诊断准确性。
■我们收集了28名COPD患者的62次夜间心电图(ECG)记录。校正心率的QT间期(QTc,Bazett)在1分钟的时间内平均并量化,无论是通过算法还是通过光标辅助手评分。手动评分是对算法得出的结果不知情的。计算了三个阈值(460、480和500ms)的Bland-Altman统计数据和混淆矩阵。
■手动和计算机分析了总共32944个1-min周期和相应的平均QTc间隔。手动和基于算法的QTc间隔之间的平均差为-1ms,协议限制为-18到16ms。总的来说,2587(8%),357(1%),和0个超过阈值460、480和500ms的QTc间隔,分别,是通过手工评分识别的。其中,2516、357和0被该算法一致地识别。这导致诊断分类准确率为0.98(95%CI0.98/0.98),1.00(1.00/1.00),和1.00(1.00/1.00),持续460、480和500ms,分别。灵敏度分别为0.97、1.00和460、480和500ms的NA,分别。460、480和500ms的特异性分别为0.98、1.00和1.00,分别。
■总的来说,在稳定的COPD患者中,有8%的夜间1分钟时间显示出临床相关的QTc延长。自动QTc算法以非常高的灵敏度和特异性准确地识别临床相关的QTc延长。使用这个工具,医院睡眠实验室可以识别无症状的QTc延长患者有恶性心律失常的风险,允许他们在最终的心脏事件之前咨询心脏病专家。
UNASSIGNED: To assess the diagnostic accuracy of a purpose-designed
QTc-scoring algorithm versus the established hand-scoring in patients with chronic obstructive pulmonary disease (COPD) undergoing sleep studies.
UNASSIGNED: We collected 62 overnight electrocardiogram (ECG) recordings in 28 COPD patients. QT-intervals corrected for heart rate (
QTc, Bazett) were averaged over 1-min periods and quantified, both by the algorithm and by cursor-assisted hand-scoring. Hand-scoring was done blinded to the algorithm-derived results. Bland-Altman statistics and confusion matrixes for three thresholds (460, 480, and 500ms) were calculated.
UNASSIGNED: A total of 32944 1-min periods and corresponding mean
QTc-intervals were analysed manually and by computer. Mean difference between manual and algorithm-based
QTc-intervals was -1ms, with limits of agreement of -18 to 16ms. Overall, 2587 (8%), 357 (1%), and 0 QTc-intervals exceeding the threshold 460, 480, and 500ms, respectively, were identified by hand-scoring. Of these, 2516, 357, and 0 were consistently identified by the algorithm. This resulted in a diagnostic classification accuracy of 0.98 (95% CI 0.98/0.98), 1.00 (1.00/1.00), and 1.00 (1.00/1.00) for 460, 480, and 500ms, respectively. Sensitivity was 0.97, 1.00, and NA for 460, 480, and 500ms, respectively. Specificity was 0.98, 1.00, and 1.00 for 460, 480, and 500ms, respectively.
UNASSIGNED: Overall, 8% of nocturnal 1-min periods showed clinically relevant QTc prolongations in patients with stable COPD. The automated
QTc-algorithm accurately identified clinically relevant
QTc-prolongations with a very high sensitivity and specificity. Using this tool, hospital sleep laboratories may identify asymptomatic patients with QTc-prolongations at risk for malignant arrhythmia, allowing them to consult a cardiologist before an eventual cardiac event.