Relation between QT interval variability and cardiac sympathetic activity in hypertension
Relation between QT interval variability and cardiac sympathetic activity in hypertension
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DOI：
10.1152/ajpheart.01184.2010
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发表时间：
2011-04-01
影响因子：
4.8
通讯作者：
Lambert, Gavin
中科院分区：
文献类型：
--
作者：
Baumert, Mathias;Schlaich, Markus P.;Lambert, Gavin
Baumert M，Schlaich MP，Nalivaiko E，Lambert E，Ika Sari C，Kaye DM，Elser MD，Sanders P，Lambert G.高血压QT间期变异性与心交感神经活动的关系。Am J Physiol Heart Circ Physiol 300：H1412-H1417，2011.首次发表于2011年1月21日; doi：10.1152/ajpheart.01184.2010.- QT间期变异性升高是恶性室性心律失常的预测因子，但其潜在机制尚不完全清楚。最近一项对起搏诱导心力衰竭犬的研究表明，QT变异性与心脏交感神经活动有关。本研究的目的是确定原发性高血压患者心脏交感神经活动增加是否与QT间期变异性增加相关。我们记录了23例原发性高血压患者和9例正常血压对照者的静息状态下去甲肾上腺素（NE）向冠状窦的溢出和单导联、短期、高分辨率体表心电图。为了评估逐搏QT间期变异性，我们计算了总体QT变异性（QTVN）以及QT变异性指数（QTVi）。与血压正常者相比，高血压患者的心脏NE溢出（12.2 ± 6.5 vs. 20.7 ± 14.7，P = 0.03）和QTVi（-1.75 ± 0.36 vs. -1.42 ± 0.50，P = 0.05）显著增加。QTVN与心脏NE溢出（r（2）= 0.31，P = 0.001）、RR变异（r（2）= 0.20，P = 0.008）和收缩压（r（2）= 0.16，P = 0.02）显著相关。线性回归分析表明前两者是QTVN的独立预测因素。总之，复极不稳定性升高与原发性高血压患者的交感神经心脏激活直接相关。
Baumert M, Schlaich MP, Nalivaiko E, Lambert E, Ika Sari C, Kaye DM, Elser MD, Sanders P, Lambert G. Relation between QT interval variability and cardiac sympathetic activity in hypertension. Am J Physiol Heart Circ Physiol 300: H1412-H1417, 2011. First published January 21, 2011; doi:10.1152/ajpheart.01184.2010.-Elevated QT interval variability is a predictor of malignant ventricular arrhythmia, but the underlying mechanisms are incompletely understood. A recent study in dogs with pacing-induced heart failure suggests that QT variability is linked to cardiac sympathetic nerve activity. The aim of this study was to determine whether increased cardiac sympathetic activity is associated with increased beat-to-beat QT interval variability in patients with essential hypertension. We recorded resting norepinephrine (NE) spillover into the coronary sinus and single-lead, short-term, high-resolution, body-surface ECG in 23 patients with essential hypertension and 9 normotensive control subjects. To assess beat-to-beat QT interval variability, we calculated the overall QT variability (QTVN) as well as the QT variability index (QTVi). Cardiac NE spillover (12.2 +/- 6.5 vs. 20.7 +/- 14.7, P = 0.03) and QTVi (-1.75 +/- 0.36 vs. -1.42 +/- 0.50, P = 0.05) were significantly increased in hypertensive patients compared with normotensive subjects. QTVN was significantly correlated with cardiac NE spillover (r(2) = 0.31, P = 0.001), with RR variability (r(2) = 0.20, P = 0.008), and with systolic blood pressure (r(2) = 0.16, P = 0.02). Linear regression analysis identified the former two as independent predictors of QTVN. In conclusion, elevated repolarization lability is directly associated with sympathetic cardiac activation in patients with essential hypertension.