Percutaneous method for multiple epicardial monophasic action potential recordings during magnetocardiographic mapping in intact rats.

Riccardo Fenici, Donatella Brisinda

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Asurgical approach for subdiaphragmatic-programmed electrical stimulation (PES) in mice has been reported by Gutstein et al. [D.E. Gutstein, S.B. Danik, J.B. Sereysky, G.E. Morley, G.I. Fishman, Subdiaphragmatic murine electrophysiological studies: sequential determination of ventricular refractoriness and arrhythmia induction, Am J Physiol Heart Circ Physiol. 285 (3) (2003) H1091-96.]. We developed a percutaneous method to drive a patented magnetocardiography- compatible amagnetic catheter (AC), specifically designed for multiple monophasic action potentials (Multi-MAP) recording, at the epicardium of spontaneously breathing small animals. The aim of this study was to test the feasibility of simultaneous magnetocardiographic (MCG) estimate of ventricular repolarization (VR) and Multi-MAP recording in 5 rats. Under fluoroscopic control, the AC was introduced with a sub-xyphoid puncture, in all animals, and moved at several epicardial sites until 4 stable MAPs were recorded, with a fixed inter-electrode distance of 1 mm. An unshielded 36-channel DC-SQUID system (sensitivity 20 fT/Hz 1/ 2) was used to record the MCG. MAP signals, differentially amplified and filtered at DC-500 Hz, were digitized at 1 kHz. The same AC was used for programmed PES at pacing cycles between 200 and 250 ms. Ventricular effective refractory period (VERP) was evaluated with the accuracy of 2 ms. MAP duration (MAPd) was measured, at 90% levels of repolarization. SimultaneousMCGand MAP recordings were successful in all animals. One rat died for respiratory arrest. Four animals tolerated well the procedure and survived. In WRs, MAPd 90% and VERP were 67±9.4 ms and 69.6±5.6 ms, respectively. This minimally invasive method is well tolerated, avoids animal sacrifice, can be used to validate the accuracy of surface MCG estimate of dispersion of VR and for assessment of arrhythmogenic potential of new drugs.
Original languageEnglish
Title of host publicationNew frontiers in biomagnetism : proceedings of the 15th International Conference on Biomagnetism
Pages480-483
Number of pages4
Publication statusPublished - 2007
Externally publishedYes
EventNew frontiers in biomagnetism : proceedings of the 15th International Conference on Biomagnetism, - Vancouver Canada
Duration: 1 Jan 2007 → …

Publication series

NameINTERNATIONAL CONGRESS SERIES

Conference

ConferenceNew frontiers in biomagnetism : proceedings of the 15th International Conference on Biomagnetism,
CityVancouver Canada
Period1/1/07 → …

Keywords

  • CARDIAC MAPPING
  • MAGNETOCARDIOGRAPHY
  • MONOPHASIC ACTION POTENTIAL
  • WISTAR RAT

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