PDF(Pubmed)
Abstract：
The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria. The classical paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces, reflected in the augmented QRS amplitude. However, the low sensitivity of voltage criteria has been repeatedly documented. We discuss possible reasons for this shortcoming and proposal of a new paradigm. The theoretical background for voltage measured at the body surface is defined by the solid angle theorem, which relates the measured voltage to spatial and non-spatial determinants. The spatial determinants are represented by the extent of the activation front and the distance of the recording electrodes. The non-spatial determinants comprise electrical characteristics of the myocardium, which are comparatively neglected in the interpretation of the QRS patterns. Various clinical conditions are associated with LVH. These conditions produce considerable diversity of electrical properties alterations thereby modifying the resultant QRS patterns. The spectrum of QRS patterns observed in LVH patients is quite broad, including also left axis deviation, left anterior fascicular block, incomplete and complete left bundle branch blocks, Q waves, and fragmented QRS. Importantly, the QRS complex can be within normal limits. The new paradigm stresses the electrophysiological background in interpreting QRS changes, i.e., the effect of the non-spatial determinants. This postulates that the role of ECG is not to estimate LV size in LVH, but to understand and decode the underlying electrical processes, which are crucial in relation to cardiovascular risk assessment.
摘要：
LVH的ECG诊断主要基于QRS电压标准。经典范式假设左心室质量增加会产生更强的电场，增加向左和向后QRS力，反映在增强的QRS振幅中。然而,电压标准的低灵敏度已被反复记录。我们讨论了这一缺点的可能原因，并提出了新的范式。在体表测量的电压的理论背景由立体角定理定义，这将测量的电压与空间和非空间决定因素相关联。空间决定因素由激活前沿的范围和记录电极的距离表示。非空间决定因素包括心肌的电特性，这在QRS模式的解释中相对被忽视。各种临床病症与LVH相关。这些条件产生相当多样的电性质改变,从而修改所得QRS模式。在LVH患者中观察到的QRS图的频谱相当广泛，还包括左轴偏差，左前分支传导阻滞,不完整和完整的左束支传导阻滞，Q波,和零散的QRS。重要的是,QRS波群可以在正常范围内。新范式强调了解释QRS变化的电生理背景，即，非空间决定因素的影响。这假设心电图的作用不是估计LVH中的LV大小，但是要理解和解码潜在的电气过程，这对心血管风险评估至关重要。
