Ueki M, Nakaya Y, Fujino K, Nomura M, Saito Y, Fujimoto T, Kiyoshige K, Saito K, Hiasa Y, Mori H
Second Department of Internal Medicine, School of Medicine, University of Tokushima, Japan.
J Electrocardiol. 1987 Nov;20(5):383-90. doi: 10.1016/s0022-0736(87)80090-0.
The U loop of the vectorcardiogram (VCG) was examined qualitatively and quantitatively in 126 normal subjects, 15 subjects with complete right bundle branch block (CRBBB group) and 58 patients with right ventricular overloading (RVO group), using a direct-writing vectorcardiograph with memory function. In normal subjects the U loop was directed similarly to the T loop, i.e., to the left, anteriorly and inferiorly. In the CRBBB group, maximum U vector was smaller, but its direction was not significantly different from that in normal subjects. In the RVO group, the U loop tended to be displaced posteriorly and to the left and was significantly greater in magnitude than that in normal subjects in the horizontal (P less than 0.01) and frontal (P less than 0.001) planes. In the RVO group, a good correlation was found between the direction of maximum U vector and right ventricular systolic pressure. In some cases of the RVO group, the U loop was the only abnormality suggesting right ventricular overloading. These findings suggest that abnormality of the U loop is a good indicator in a diagnosis of right ventricular overloading.
采用具有记忆功能的直接记录式心电向量图仪，对126名正常受试者、15名完全性右束支传导阻滞患者（CRBBB组）和58名右心室负荷过重患者（RVO组）的心电向量图U环进行了定性和定量研究。在正常受试者中，U环的方向与T环相似，即向左、向前和向下。在CRBBB组中，最大U向量较小，但其方向与正常受试者无显著差异。在RVO组中，U环倾向于向后和向左移位，在水平（P<0.01）和额面（P<0.001）平面上其幅度明显大于正常受试者。在RVO组中，最大U向量方向与右心室收缩压之间存在良好的相关性。在RVO组的某些病例中，U环是提示右心室负荷过重的唯一异常表现。这些发现表明，U环异常是诊断右心室负荷过重的良好指标。
