TY - JOUR
T1 - Magnetocardiographic Differences of Ventricular Repolarization Parameters between Wistar Rats and Guinea Pigs
AU - Fenici, Riccardo
AU - Brisinda, Donatella
AU - Meloni, Anna Maria
PY - 2006
Y1 - 2006
N2 - The morphology and range of duration of the action potential (AP) in normal
Wistar rat's (WR) myocyte markedly differ from those of guinea pigs (GP), whose
plateau (phase 2) duration is longer. Thus a clear-cut T wave can be easy defined
in GP but not in WR. Aim of this study was to differentiate magnetocardiographic
(MCG) ventricular repolarization (VR) parameters of healthy adult WR and
GP.METHODS: 10 female animals (5 Guinea pigs and 5 Wistar rats) were studied with
a 36-channel MCG system (sensitivity of 20 fT/square root of Hz1/2) and with one
ECG lead, in an unshielded hospital room. To assess VR, HR-corrected, JTpeak,
JTend, Tpeak-end and QTend, intervals were measured from both MCG waveforms.
Timing was improved by MCG maps analysis. Magnetic field orientation (MFO), its
dynamics (MFD) and stability (JTS) during the JT interval, were also
automatically computed from MCG maps.
RESULTS: All repolarization intervals were significantly shorter in WR than in
GP, except the Tpeak-end, which was longer. MFO and MFD also differed.
CONCLUSIONS: MCG estimate of VR parameters, in adult WR and GP, is precise enough
to evidence breed-related differences, consistent with physiological
heterogeneity of duration during phases 2 and 3 of the AP, and with an higher
degree of transmural dispersion of repolarization in WR.
AB - The morphology and range of duration of the action potential (AP) in normal
Wistar rat's (WR) myocyte markedly differ from those of guinea pigs (GP), whose
plateau (phase 2) duration is longer. Thus a clear-cut T wave can be easy defined
in GP but not in WR. Aim of this study was to differentiate magnetocardiographic
(MCG) ventricular repolarization (VR) parameters of healthy adult WR and
GP.METHODS: 10 female animals (5 Guinea pigs and 5 Wistar rats) were studied with
a 36-channel MCG system (sensitivity of 20 fT/square root of Hz1/2) and with one
ECG lead, in an unshielded hospital room. To assess VR, HR-corrected, JTpeak,
JTend, Tpeak-end and QTend, intervals were measured from both MCG waveforms.
Timing was improved by MCG maps analysis. Magnetic field orientation (MFO), its
dynamics (MFD) and stability (JTS) during the JT interval, were also
automatically computed from MCG maps.
RESULTS: All repolarization intervals were significantly shorter in WR than in
GP, except the Tpeak-end, which was longer. MFO and MFD also differed.
CONCLUSIONS: MCG estimate of VR parameters, in adult WR and GP, is precise enough
to evidence breed-related differences, consistent with physiological
heterogeneity of duration during phases 2 and 3 of the AP, and with an higher
degree of transmural dispersion of repolarization in WR.
KW - Guinea pig
KW - Magnetocardiography
KW - Ventricular repolarization
KW - Wistar rat
KW - Guinea pig
KW - Magnetocardiography
KW - Ventricular repolarization
KW - Wistar rat
UR - http://hdl.handle.net/10807/17785
M3 - Article
SN - 1538-4098
SP - 383
EP - 384
JO - NEUROLOGY & CLINICAL NEUROPHYSIOLOGY
JF - NEUROLOGY & CLINICAL NEUROPHYSIOLOGY
ER -