TY - JOUR
T1 - Contactless magnetocardiographic mapping in anesthetized Wistar rats: evidence
of age-related changes of cardiac electrical activity.
AU - Brisinda, Donatella
AU - Caristo, Maria Emiliana
AU - Fenici, Riccardo
AU - FACOLTA', DI MEDICINA E CHIRURGIA "A.GEMELLI"
PY - 2006
Y1 - 2006
N2 - Magnetocardiography (MCG) is the recording of the magnetic field (MF) generated
by cardiac electrophysiological activity. Because it is a contactless method, MCG
is ideal for noninvasive cardiac mapping of small experimental animals. The aim
of this study was to assess age-related changes of cardiac intervals and
ventricular repolarization (VR) maps in intact rats by means of MCG mapping.
Twenty-four adult Wistar rats (12 male and 12 female) were studied, under
anesthesia, with the same unshielded 36-channel MCG instrumentation used for
clinical recordings. Two sets of measurements were obtained from each animal: 1)
at 5 mo of age (297.5 +/- 21 g body wt) and 2) at 14 mo of age (516.8 +/- 180 g
body wt). RR and PR intervals, QRS segment, and QTpeak, QTend, JTpeak, JTend, and
Tpeak-end were measured from MCG waveforms. MCG imaging was automatically
obtained as MF maps and as inverse localization of cardiac sources with
equivalent current dipole and effective magnetic dipole models. After 300 s of
continuous recording were averaged, the signal-to-noise ratio was adequate for
study of atrial and ventricular MF maps and for three-dimensional localization of
the underlying cardiac sources. Clear-cut age-related differences in VR duration
were demonstrated by significantly longer QTend, JTend, and Tpeak-end in older
Wistar rats. Reproducible multisite noninvasive cardiac mapping of anesthetized
rats is simpler with MCG methodology than with ECG recording. In addition, MCG
mapping provides new information based on quantitative analysis of MF and
equivalent sources. In this study, statistically significant age-dependent
variations in VR intervals were found.
AB - Magnetocardiography (MCG) is the recording of the magnetic field (MF) generated
by cardiac electrophysiological activity. Because it is a contactless method, MCG
is ideal for noninvasive cardiac mapping of small experimental animals. The aim
of this study was to assess age-related changes of cardiac intervals and
ventricular repolarization (VR) maps in intact rats by means of MCG mapping.
Twenty-four adult Wistar rats (12 male and 12 female) were studied, under
anesthesia, with the same unshielded 36-channel MCG instrumentation used for
clinical recordings. Two sets of measurements were obtained from each animal: 1)
at 5 mo of age (297.5 +/- 21 g body wt) and 2) at 14 mo of age (516.8 +/- 180 g
body wt). RR and PR intervals, QRS segment, and QTpeak, QTend, JTpeak, JTend, and
Tpeak-end were measured from MCG waveforms. MCG imaging was automatically
obtained as MF maps and as inverse localization of cardiac sources with
equivalent current dipole and effective magnetic dipole models. After 300 s of
continuous recording were averaged, the signal-to-noise ratio was adequate for
study of atrial and ventricular MF maps and for three-dimensional localization of
the underlying cardiac sources. Clear-cut age-related differences in VR duration
were demonstrated by significantly longer QTend, JTend, and Tpeak-end in older
Wistar rats. Reproducible multisite noninvasive cardiac mapping of anesthetized
rats is simpler with MCG methodology than with ECG recording. In addition, MCG
mapping provides new information based on quantitative analysis of MF and
equivalent sources. In this study, statistically significant age-dependent
variations in VR intervals were found.
KW - CARDIAC MAPPING
KW - MAGNETOCARDIOGRAPHY
KW - WISTAR RAT
KW - CARDIAC MAPPING
KW - MAGNETOCARDIOGRAPHY
KW - WISTAR RAT
UR - http://hdl.handle.net/10807/17790
M3 - Article
SP - h368-h378
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
SN - 0363-6135
ER -