The Role of anisotropy on the initiation and propagation of action currents in cardiac tissue
Abstract
A central question in biomagnetism is whether the biomagnetic field can contain information not present in the bioelectric potential. We have examined the physiological basis of magnetically-detectable but electrically silent sources, and identified the roles of tissue anisotropy and the spiral architecture of the heart: electrically silent current loops can in principle flow perpendicular to the direction of propagation. We have conducted experiments using an ultra high resolution scanning SQUID microscope in combination with epi-fluorescence imaging system to measure the action currents and the transmembrane potentials of a propagating wavefront in a Langendorff perfused rabbit heart. An activation wavefront has been induced on either the leftventricular free wall or the appex. Results show characteristic differences in the propagation velocities as a function of angle, which provide strong evidence for electrically silent sources.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARY23009B