Katayama M, Nakaya Y
2nd Department of Internal Medicine, School of Medicine, University of Tokushima, Japan.
Tokushima J Exp Med. 1990 Jun;37(1-2):9-21.
The diagnosis of right ventricular overload is often difficult by the electrocardiogram (ECG) when it is associated with right bundle branch block (RBBB). In this study, we examined the usefulness of the MCG in diagnosis of right ventricular diastolic overload and clarified the features of the magnetocardiogram (MCG) of patients with right ventricular overload with RBBB. In our previous studies, we found that MCG criteria shows higher sensitivity in diagnosis of right ventricular hypertrophy, but the criteria showed higher false positivity in patients with RBBB without any underlying disease (RBBB group). Therefore, we set different MCG criteria for right ventricular diastolic overload (RVO-d) as follows based on the mean +/- 2SD of the RBBB group: 1) R wave at C-3 (Rc-3)greater than or equal to 25 x 10(-12)tesla, 2) S wave at F-4 (SF-4)greater than or equal to 11 x 10(-12)tesla. In patients with a right ventricular pressure of more than 50 mmHg, the MCG criteria showed higher sensitivity and specificity than the ECG criteria. These results suggest that the MCG is useful for diagnosis of right ventricular diastolic overload with RBBB.
当右心室负荷过重与右束支传导阻滞（RBBB）相关时，通过心电图（ECG）往往难以诊断。在本研究中，我们检验了心磁图（MCG）在诊断右心室舒张期负荷过重中的作用，并阐明了合并RBBB的右心室负荷过重患者的心磁图（MCG）特征。在我们之前的研究中，我们发现MCG标准在诊断右心室肥厚时显示出更高的敏感性，但在无任何基础疾病的RBBB患者（RBBB组）中该标准显示出更高的假阳性率。因此，我们基于RBBB组的均值±2标准差，为右心室舒张期负荷过重（RVO-d）设定了如下不同的MCG标准：1）C-3导联的R波（Rc-3）≥25×10⁻¹²特斯拉，2）F-4导联的S波（SF-4）≥11×10⁻¹²特斯拉。在右心室压力超过50 mmHg的患者中，MCG标准显示出比ECG标准更高的敏感性和特异性。这些结果表明，MCG有助于诊断合并RBBB的右心室舒张期负荷过重。
