MAPPING OF BODY-SURFACE POTENTIALS IN PATIENTS WITH THE IDIOPATHIC LONG QT SYNDROME
MAPPING OF BODY-SURFACE POTENTIALS IN PATIENTS WITH THE IDIOPATHIC LONG QT SYNDROME
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DOI：
10.1161/01.cir.74.6.1334
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发表时间：
1986-12-01
期刊：
影响因子：
37.8
通讯作者：
SCHWARTZ, PJ
中科院分区：
文献类型：
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作者：
DEAMBROGGI, L;BERTONI, T;SCHWARTZ, PJ
记录了25例特发性长QT综合征（LQTS）患者和25例年龄和性别相匹配的健康对照者的140个胸导联的体表电位图。在每个导联点计算Q间期和ST-T间期的潜在时间积分，并显示为等积分（ISOI）图。在QST和ST-T ISOI图上观察到的主要异常是右前和右下胸部的一个负值区域大于正常值，以及积分值的复杂多峰分布。在19例（76%）LQTS患者和4例（16%）对照受试者中至少存在一种异常（p <0.001）。每个ISOI图也表示为九个基本分量（特征向量）的加权和，以检测和定量非偶极含量。LQTS组非偶极特征向量（第三个以外的所有特征向量）的贡献百分比显著高于对照组（p <0.005）。特别是，在QQTS ISOI图上观察到异常高的非偶极含量在LQTS患者中比对照受试者更频繁（9或36% vs 1或4%），在ST-T ISOI图上也是如此（14或56% vs 1或4%）。体表心电图主要异常与晕厥发作无相关性。然而，这些改变在LQTS患者中的高患病率（76%）和在对照人群中的罕见发生强烈表明它们可能是诊断非典型病例的有用标志物。胸前显著的电负性区域可能与心脏前壁部分的延迟复极有关。这一发现与右心交感神经活性低于正常是LQTS主要发病机制的假说一致。多峰分布和高非偶极含量提示心室恢复过程中的局部电差异。这可能部分解释了LQTS患者对恶性心律失常的高度易感性。
Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idiopathic long QT syndrome (LQTS) and in 25 healthy control subjects matched for age and sex. Potential time integrals of the QRST and ST-T intervals were calculated at each lead point and displayed as isointegral (ISOI) maps. The main abnormalities noted on the QRST and ST-T ISOI maps were one area of negative values larger than normal in the right anterior and inferior thorax and a complex multipeak distribution of the integral values. At least one abnormality was present in 19 (76%) of the patients with LQTS and four (16%) of the control subjects (p less than .001). Each ISOI map was also represented as a weighted sum of nine fundamental components (eigenvectors) to detect and quantitate the nondipolar content. The percent contribution of the nondipolar eigenvectors (all eigenvectors beyond the third) was significantly higher in the LQTS group than in the control group (p less than .005). Specifically, an abnormally high nondipolar content on the QRST ISOI maps was observed much more frequently for patients with LQTS than for control subjects (nine or 36% vs one or 4%), and this was also true on the ST-T ISOI maps (14 or 56% vs one or 4%). No correlation was found between the major abnormalities on body surface maps and syncopal episodes. However, the high prevalence (76%) of these alterations among the patients with LQTS and their infrequent occurrence in the control population strongly suggests that they may be useful markers for the diagnosis of atypical cases. The prominent electronegative area on the anterior thorax can be related to delayed repolarization of a portion of the anterior wall of the heart. This finding is in agreement with the hypothesis that lower than normal right cardiac sympathetic activity is the main pathogenetic mechanism of LQTS. Multipeak distribution and high nondipolar content suggest regional electrical disparities in the ventricular recovery process. This may in part account for the high susceptibility of patients with LQTS to malignant arrhythmias.