Smetana Peter, Batchvarov Velislav N, Hnatkova Katerina, Camm A John, Malik Marek
Department of Cardiological Sciences, St. George's Hospital Medical School, London SW17 0RE, United Kingdom.
Am J Physiol Heart Circ Physiol. 2002 May;282(5):H1889-97. doi: 10.1152/ajpheart.00962.2001.
The reason for sex differences in arrhythmic risk remains unclear. Heterogeneity of ventricular repolarization is directly linked to arrhythmogenesis; thus we investigated repolarization homogeneity and its circadian pattern in men and women. During 24-h Holter recordings in 60 healthy subjects (27 males), a 12-lead electrocardiogram (ECG) was obtained every 30 s. RR and QT intervals, and, after singular-value decomposition, two characteristics of repolarization homogeneity were calculated in each ECG. Corrected QT (QTc) values were obtained using an individually optimized heart rate (HR) correction formula. All values were averaged over 10-min time bands from 0000 to 2400. There were substantial sex differences in both global repolarization homogeneity (measured by the total cosine of the angle between QRS and T wave vectors) and regional homogeneity of repolarization (quantified independently by the relative T wave residuum). Whereas women throughout the 24 h followed more closely the pattern of inverse sequence between depolarization and repolarization, they also showed much higher localized repolarization heterogeneity than men. In both women and men, repolarization irregularity was greatest during morning hours. A sex difference was also observed for HR and QTc interval; however, the circadian patterns of the repolarization homogeneity descriptors were different from those of HR and QTc intervals.
心律失常风险存在性别差异的原因尚不清楚。心室复极的异质性与心律失常的发生直接相关；因此，我们研究了男性和女性的复极均匀性及其昼夜模式。在对60名健康受试者（27名男性）进行24小时动态心电图记录期间，每30秒获取一次12导联心电图（ECG）。计算RR和QT间期，并在奇异值分解后，计算每次心电图复极均匀性的两个特征。使用个体优化的心率（HR）校正公式获得校正QT（QTc）值。所有值在00:00至24:00的10分钟时间段内进行平均。在整体复极均匀性（通过QRS波和T波向量之间夹角的总余弦测量）和复极区域均匀性（通过相对T波残差独立量化）方面均存在显著的性别差异。在24小时内，女性更紧密地遵循去极化和复极化之间的逆序模式，但她们也表现出比男性更高的局部复极异质性。在女性和男性中，复极不规则性在早晨时段最大。在HR和QTc间期方面也观察到性别差异；然而，复极均匀性描述符的昼夜模式与HR和QTc间期的不同。
