Magnetocardiographic Differences of Ventricular Repolarization Parameters between Wistar Rats and Guinea Pigs

Riccardo Fenici, Donatella Brisinda, Anna Maria Meloni

Research output: Contribution to journalArticlepeer-review


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.
Original languageEnglish
Pages (from-to)383-384
Number of pages2
Publication statusPublished - 2006


  • Guinea pig
  • Magnetocardiography
  • Ventricular repolarization
  • Wistar rat


Dive into the research topics of 'Magnetocardiographic Differences of Ventricular Repolarization Parameters between Wistar Rats and Guinea Pigs'. Together they form a unique fingerprint.

Cite this