Magnetocardiographic study of CAD patients in an unshielded intensive care unit

Multichannel Magnetocardiography (MMCG) is a contactless technique for non invasive study of patients with exercise–induced myocardial ischemia. However so far MMCG studies of patients (pts) with coronary artery disease (CAD) had been done in magnetically shielded rooms only, which limit its clinical use to chronic pts. This study evaluated the reliability of the method in an unshielded unit for cardiac catheterization, as the first step for future investigation of critical pts with spontaneous acute ischemia. Method: 9 channels DC-SQUID MMCG system (sensitivity is 20 fT/Hz1/2) (CMI, USA), measuring grid 20 x 20 cm. 10 pts, with angiography-documented CAD were investigated at least twice, to test for the reproducibility. Analysis was according to Hänninen et al (A.N.E.2000;5(2):147-157). Results: Magnetic field orientation ( angle), of the integral of the second quarter from the J-point was abnormal (266.2±52) in 6/10 pts, that of the T wave apex was normal (47.2±21.4) in all. Conclusion: MMCG can be performed in an unshielded hospital intensive care room, with quality good enough for non-contact monitoring and imaging of time evolution of acute myocardial ischemia