Transcript Normal MCG - Click on this File

Magnetocardiogram
of a Healthy Individual
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Patient With Normal Coronary
Arteries
Demographic data
Basic parameters
Gender
Age
BMI
HR
BP
EF
female
65
31
80
130:80
--
Risk factors
DM
HT
Prior MI
Prior CAD
Smoker
HLP
no
no
no
no
yes
no
Other test results
ECG
ECHO
TNI
Indication
normal
normal
normal
ACS
Coronary Angiography
LAD
stenosis
location
LCX
stenosis
location
RCA
stenosis
location
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Atrial Activity of the Normal Control
The vector in the animated colour magnetic field map depicts the location and orientation of a
magnetic dipole that is equivalent to the source of the electric activity. Interpretation of the
vector’s dynamics (changes over time) helps understanding the underlying electrical process.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Right Atrial Depolarization
The history of vectors indicates that
the electric activity in the right
atrium is uniform and focused.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Left Atrial Depolarization
A clean transition of electrical
activity from right to left atrium is
visible.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Atrial Repolarization
Electric activity during atrial
repolarization is directed opposite
to depolarization. Due to lower
signal strength its interpretation
requires experience. In case of an
accessory pathway a second dipolar
structure would be visible. Note: for
better visibility only the beginning
of atrial repolarization is shown.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Depolarization of the Intraventricular Septum
The AV node carries the activity to
the intraventricular septum, which
depolarizes. The electric current
propagates along the septum until it
reaches the apex.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Ventricular Depolarization
The ventricles depolarize. The map
shows a superposition of LV and RV
activity. The LV free wall’s magnetic
signature dominates over that of the
RV. However, the effect of a conduction
abnormality in the RV would be visible
indirectly through a change in pattern
and polarity.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Late Ventricular Depolarization
The electric activity moves from
anterior to posterior indicated by an
increasing distance of the two maxima.
Note that the polarity of the magnetic
field flips by 180 degrees. The 3D
animation nicely reflects the spatial
propagation of the vector.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
The ‘ST Segment’
The ST segment in the normal MCG is rather flat: MCG traces in the butterfly plot are bundled densely.
The map often shows a random distribution of magnetic fields. This is due to the fact that cardiac electric
activity is close to zero thus leading to a very small signal to noise ratio. In the present case it can be
concluded that the remaining activity in the ST segment is mostly due to non-cardiac sources (noise).
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA
Ventricular Repolarization
In the normal heart repolarization usually
begins in the last area of the heart to have
been depolarized, and then travels
backward, in the opposite direction of the
wave of depolarization. The approaching
wave of depolarization and the receding
wave of repolarization generate similar
field maps both in pattern and polarity. The
normal
heart
shows
a
uniform,
homogenous, and stable field distribution.
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Copyright © 2005 CardioMag Imaging, Inc. (CMI) 450 Duane Av, Schenectady, NY 12304, USA