Repolarization spatial-time current abnormalities in patients with coronary heart disease
Kuniomi Ogata1, Akihiko Kandori, Yasushi Watanabe
1Advanced Research Laboratory, Hitachi Ltd., Higashi-Koigakubo, Kokubunji, Tokyo, Japan. kuniomi.ogata.fb@hitachi.com
Insights
Magnetocardiography (MCG) current distribution parameters (CDPs) can identify coronary heart disease (CHD) abnormalities. A scoring system using maximum and total current vectors during repolarization shows promise for diagnosing CHD.
Area of Science:
- Biophysics
- Cardiology
- Medical Imaging
Background:
- Magnetocardiography (MCG) visualizes myocardial current distribution.
- Current distribution parameters (CDPs) assess spatial-time current abnormalities in coronary heart disease (CHD).
- Standardized criteria for CDP-based CHD abnormality scoring remain under development.
Purpose of the Study:
- To evaluate the effectiveness of CDPs in distinguishing between normal controls and CHD patients.
- To develop and validate a scoring method for CHD abnormalities using CDPs.
Main Methods:
- MCG signals were acquired from 101 controls and 56 CHD patients.
- Analyzed CDPs including maximum current vector (MCV) and total current vector (TCV) during ventricular repolarization.
- Calculated areas under the receiver operating characteristic curve (A(z)) and developed a total score (0-4) based on four high-A(z) CDPs.
Main Results:
- MCV and TCV angles at T-wave peak, and TCV angular differences, showed high diagnostic accuracy (A(z)).
- The averaged total score was significantly higher in triple-vessel disease patients (2.67) than controls (0.53).
- A total score >1 yielded 85.7% sensitivity and 74.3% specificity for suspected CHD.
Conclusions:
- A scoring system using MCV and TCV during repolarization effectively reflects lesion areas in CHD.
- This scoring method can indicate time changes in electrical activation dispersion due to ischemia.
- The proposed criteria and scoring offer a promising approach for diagnosing CHD using MCG.
Background:
Magnetocardiography (MCG) is a new technique for visualizing a current distribution in the myocardium. In recent years, current distribution parameters (CDPs) have been developed based on the distribution. The CDPs reflect spatial-time current abnormalities in patients with coronary heart disease (CHD). However, the criteria and scoring method of the abnormalities using CDPs are still controversial.
Method:
We measured MCG signals for 101 normal controls and 56 CHD patients (single-, double-, and triple-vessel diseases) using a MCG system. The CDPs (maximum current vector [MCV], total current vector [TCV], current integral map, and current rotation) during ventricular repolarization were analyzed. To evaluate the CDPs that are effective in distinguishing between normal controls and CHD patients, the areas under the receiver operating characteristic curve (A(z)) are calculated. Furthermore, the total scores ("0" to "4") of four CDPs with high A(z) values are also calculated.
Results:
MCV and TCV angles at the T-wave peak had the highest A(z) value. Furthermore, TCV angular differences between the ST-T segment also had high A(z) values. Using the four CDPs, the averaged total score for patients with triple-vessel disease was the highest ("2.67") compared to the other groups (normal controls: 0.53). Furthermore, based on the assumption that subjects with a total score over "1" were suspected of having CHD, sensitivity and specificity were 85.7% and 74.3%, respectively.
Conclusion:
We concluded that the score and criteria using MCV and TCV during repolarization in CHD patients can reflect lesion areas and time changes of electrical activation dispersion due to ischemia.
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