Mariko Katayama

Analysis of the T wave of the magnetocardiogram in patients with essential hypertension by means of isomagnetic and vector arrow maps

Magnetocardiograms (MCGs) of 50 normal subjects and 40 patients with essential hypertension were recorded to determine the value of the MCG for detecting abnormal repolarization. Among the patients with essential hypertension, there were nine cases (22.5%) in whom isopotential maps did not show rightward repolarization vectors but isomagnetic and vector arrow maps showed a rightward repolarization vector in some areas in addition to the normal repolarization vector. Departure maps of the ECG showed an increased repolarization vector directed anteriorly in some of these cases. The repolarization abnormality was recognized in only the MCG departure map in four cases, while no case showed abnormality in only the ECG departure map. With the progress of hypertension, the repolarization abnormality was seen more frequently and its detection using the MCG was higher than that using the ECG. Furthermore, multiple dipoles were detected more frequently from the MCG than from the ECG. Thus the MCG seems more useful than the ECG in the analysis of repolarization abnormalities in essential hypertension.

Detection of Accessory Pathway in Patients with WPW Syndrome by Means of The Isomagnetic Map and MRI

The current source is expected to be localized more exactly with a magnetocardiogram (MCG) than with an electrocardiogram (ECG). In the present study, the isomagnetic map at the time of the delta wave and a gated magnetic resonance imaging (MRI) were compared to assess the usefulness of the magnetocardiogram (McG) in localizing a position of the accessory pathway (Kent bundle). Spach and Benson reported that the analysis of the T wave was as useful as that of the QRS wave in predicton of the pre-excited sites of the ventricle. 1,2 Therefore, we examined the repolarization wave in order to localize the site of an accessory pathway in WPW syndrome, because the repolarization abnormality might be detected more precisely by the MCG. 3 Our results showed that the analysis of the repolarization wave’s of the MCG was as useful as the delta wave to detect the site of an accessory pathway.

U wave of high-speed and magnified electrocardiogram in left ventricular overloading

In this study we examined by high speed and magnified electrocardiography the quantitative characteristics of the U wave and the clinical significance of a negative U wave in patient with left ventricular over loading. This method permitted more quantitative measurement of the U wave than the ECG at normal magnification (standard ECG)

The Magnetocardiogram in Patients with Systolic and Diastolic Overload of the Right Ventricle

The second derivative gradiometer is expected to detect the current source from the right ventricle more specifically, where it is located close to the anterior chest wall because of its unique system. Therefore, we investigated the magnetocardiogram (MCG) in patients with right ventricular overload (RVO), and correlated the MCG findings with hemodynamic parameters. This study was also aimed to diagnose RVO in the presence of right bundle branch block (RBBB), which so far has been considered to be difficult to diagnose by the conventional electrocardiogram (ECG).

Detection of the Abnormal Repolarization Vector in Diabetes Mellitus by Means of the Isomagnetic Map

The magnetocardiogram (MCG) recorded with the second-derivative SQUID gradiometer may be more useful to detect the current source parallel to the anterior chest wall and multiple current dioples than the electrocardiogram (ECG). We have already reported that the abnormal repolarization vector could be detected more frequently by the MCG than ECG in patient with left ventricular overloading and myocardial infarction. 1,2 In the present study, we investigated the clinical usefulness of the isomagnetic map analysis for the diagnosis of repolarization abnormality in diabetic patients.