Draisma Harmen H M, Schalij Martin J, van der Wall Ernst E, Swenne Cees A
Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
Heart Rhythm. 2006 Sep;3(9):1092-9. doi: 10.1016/j.hrthm.2006.05.025. Epub 2006 Jun 15.
The ventricular gradient, a notion conceived by Wilson et al during the 1930s, has contributed considerably to a better understanding of the ECG manifestations of the cardiac repolarization process. The power of the ventricular gradient is its ability to assess the primary factors that contribute to the T wave (i.e., heterogeneity of action potential morphology throughout the ventricles) in the presence of secondary factors contributing to the T wave (i.e., heterogeneity in ventricular depolarization instants). Where T-wave morphology is an ECG expression of heterogeneity of the repolarization, the ventricular gradient discriminates between primary or secondary causes of such heterogeneity. Besides the spatial ventricular gradient (Burger's three-dimensional elaboration of Wilson's two-dimensional concept), body surface mapping of local components of the ventricular gradient has emerged as a technique for assessing local ventricular action potential duration heterogeneity. The latter is believed to contribute to localization of arrhythmogenic areas in the heart. The spatial ventricular gradient, which can be computed on the basis of a regular routine ECG and does not require body surface mapping, aims to assess the overall heterogeneity of ventricular action potential morphology. This review addresses the nature and diagnostic potential of the spatial ventricular gradient. The main focus is the role of the spatial ventricular gradient in ECG assessment of dispersion of repolarization, a key factor in arrhythmogeneity.
心室梯度是威尔逊等人在20世纪30年代提出的概念，对更好地理解心脏复极化过程的心电图表现有很大帮助。心室梯度的作用在于，在存在影响T波的次要因素（即心室去极化瞬间的异质性）时，它能够评估导致T波的主要因素（即整个心室动作电位形态的异质性）。当T波形态是复极化异质性的心电图表现时，心室梯度能够区分这种异质性的主要或次要原因。除了空间心室梯度（伯格对威尔逊二维概念的三维阐述），心室梯度局部成分的体表标测已成为评估局部心室动作电位持续时间异质性的一种技术。后者被认为有助于确定心脏中致心律失常区域的位置。空间心室梯度可根据常规心电图计算得出，无需体表标测，旨在评估心室动作电位形态的整体异质性。本综述探讨了空间心室梯度的性质和诊断潜力。主要重点是空间心室梯度在心电图评估复极化离散度中的作用，而复极化离散度是心律失常的一个关键因素。
