Integral value of JT interval in magnetocardiography is sensitive to coronary stenosis and improves soon after coronary revascularization.
BACKGROUND
Magnetocardiography (MCG) is sensitive to minute cardiac electric abnormalities, but its clinical utility in diagnosing ischemic heart disease (IHD) has not been established. The present study examined the usefulness of an integral MCG value of ventricular repolarization in patients with IHD.


RESULTS
MCG was performed at rest in 14 patients with coronary stenosis >75% confirmed by coronary angiography (IHD group) using a 64-channel system, and then the sum of the 64-channel integral values of the QRS or JT intervals (QRSi and JTi, respectively) was calculated. The JTi/QRSi value indicated the total power of currents in JT compared with those in QRS. These measurements were repeated within 2 weeks after coronary revascularization. The Control group comprised 30 healthy volunteers. The baseline value of JTi/QRSi was significantly smaller in the IHD than in the Control group, but after revascularization it increased and did not significantly differ from the Control group. No significant difference in ST deviation was identified by electrocardiography (ECG) before and after coronary revascularization. Analysis of the Control group revealed that JTi/QRSi was not affected by age.


CONCLUSIONS
The JTi/QRSi of the MCG is more sensitive to coronary stenosis than ECG, and this parameter improves soon after coronary revascularization.
On
Kei
K
Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
Watanabe
Shigeyuki
S
Yamada
Satsuki
S
Takeyasu
Noriyuki
N
Nakagawa
Yoshitsugu
Y
Nishina
Hidetaka
H
Morimoto
Takafumi
T
Aihara
Hideaki
H
Kimura
Taizo
T
Sato
Yoko
Y
Tsukada
Keiji
K
Kandori
Akihiko
A
Miyashita
Tsuyoshi
T
Ogata
Kuniomi
K
Suzuki
Daisuke
D
Yamaguchi
Iwao
I
Aonuma
Kazutaka
K
D000368:Aged; D000375:Aging / Q000502:physiology; D016022:Case-Control Studies; D023921:Coronary Stenosis / Q000175:diagnosis / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D053798:Magnetocardiography; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology; D009204:Myocardial Revascularization; D012680:Sensitivity and Specificity