Age and QT variability index during free breathing, controlled breathing and tilt in patients with chronic heart failure and healthy control subjects
Age and QT variability index during free breathing, controlled breathing and tilt in patients with chronic heart failure and healthy control subjects
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DOI：
10.1016/j.trsl.2006.02.001
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发表时间：
2006-08-01
影响因子：
7.8
通讯作者：
Magri, Damiano
中科院分区：
文献类型：
--
作者：
Piccirillo, Gianfranco;Magnanti, Marzia;Magri, Damiano
QT 变异指数 (QTVI) 表明心肌复极的时间离散性，高 QTVI 与高危受试者因恶性室性心律失常猝死的倾向相关。在这项研究中，作者评估了自由呼吸、控制呼吸和交感神经应激（倾斜）对慢性心力衰竭 (CHF) 患者和健康对照受试者 QTVI 的影响。作者还研究了年龄对相同变量的影响。为了获得规范数据，他们计算了按年龄分组的健康受试者的 95% 置信区间。在所有实验条件下，CHF 组总体和年龄亚组的 QTVI 均大于对照组。在患者和对照组中，倾斜期间 QTVI 显着增加，但自由呼吸和受控呼吸期间测量的 QTVI 之间没有发现差异。在健康对照中，以下变量与 QTVI 显着相关：年龄和基线心率 (P < 0.001)。在 CHF 患者中，年龄对 QTVI 没有影响。结论：年龄、交感神经应激和 CHF 都会增加 QTVI，并可能诱发猝死。进一步的研究应该评估 QTVI 作为预测各种风险条件下心源性猝死的标志物的有用性。
The QT variability index (QTVI) indicates temporal dispersion in myocardial repolarization, and a high QTVI is associated with a propensity for sudden death from malignant ventricular arrhythmias in subjects at high risk. In this study, the authors assessed the effects of free breathing, controlled breathing, and sympathetic stress (tilt) on the QTVI in patients with chronic heart failure (CHF) and healthy control subjects. The authors also examined the influence of age on the same variables. To obtain normative data, they calculated 95% confidence intervals for healthy subjects grouped according to age. Under all experimental conditions, the QTVI was larger in the CHF group overall and in the age subsets than in controls. In patients and controls, the QTVI increased significantly during tilt, although no differences were found between the QTVI measured during free and controlled breathing. In healthy controls, the following variables correlated significantly with the QTVI: age and baseline heart rate (P < 0.001). In patients with CHF, aging had no influence on the QTVI. Conclusion: Age, sympathetic stress, and CHF all tend to increase the QTVI and could potentially induce sudden death. Further studies should assess the usefulness of the QTVI as a marker predicting sudden cardiac death under the various conditions of risk.