title: Reproducibility of quantitative estimate of magnetocardiographic ventricular depolarization and repolarization parameters in healthy subjects and patients with coronary artery disease.
abstract: Magnetocardiography (MCG) has been introduced as an innovative non-invasive diagnostic tool to identify various heart diseases. However, there have been little data on the reliability of MCG parameters. The purpose of this study is to examine the test-retest reliability of different diagnostic parameters derived from MCG. We investigated short-, intermediate-, and long-term reliability of nine parameters from T (max/3)-T (max) interval, and five parameters from each time point such as QRS-wave, the peak of R-, and T-wave were evaluated. Short-term reliability was tested in the youngest 20 subjects (mean age = 26.3 +/- 4.9 years) in three sessions separated by 5 min. Intermediate-term reliability was tested in the 35 subjects with coronary artery disease (CAD) (65.1 +/- 7.1 years) with two recording sessions each in the morning and afternoon, separated by more than four hours. Long-term reliability was tested in seven subjects (37.1 +/- 8.8 years) using seven daily sessions. Interclass correlation coefficients (ICC) showed that test-retest reliability was good to excellent (0.99 > or = ICC > or = 0.80) for six out of nine parameters within T (max/3)-T (max). In addition, all parameters on the peak of R-wave, T-wave, and QRS-wave integrated were good to excellent (0.99 > or = ICC > or = 0.80) except for one parameter of CAD patients showing lower ICC values under 0.7. In conclusion, our study showed that the test-retest characteristics of the studied MCG parameters are generally stable and reliable over periods of minutes to days in subjects with different age spectrums.
authors.affiliation: Bio-signal Research Laboratory, Korea Research Institute of Standards and Science, Room 170, Building 201, 1 Doryong-dong, Yuseong-gu, Daejeon 305-340, Republic of Korea. hlim@kriss.re.kr
authors.forename: Hyun Kyoon
authors.initials: HK
authors.lastname: Lim
authors.forename: Namsik
authors.initials: N
authors.lastname: Chung
authors.forename: Kiwoong
authors.initials: K
authors.lastname: Kim
authors.forename: Young-Guk
authors.initials: YG
authors.lastname: Ko
authors.forename: Hyukchan
authors.initials: H
authors.lastname: Kwon
authors.forename: Yong-Ho
authors.initials: YH
authors.lastname: Lee
authors.forename: Jin-Bae
authors.initials: JB
authors.lastname: Kim
authors.forename: Jung Rae
authors.initials: JR
authors.lastname: Cho
authors.forename: Jin-Mok
authors.initials: JM
authors.lastname: Kim
authors.forename: In-Seon
authors.initials: IS
authors.lastname: Kim
authors.forename: Yong Ki
authors.initials: YK
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D053798:Magnetocardiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity