AJP - Heart and Circulatory Physiology, Vol 242, Issue 4 526-H535, Copyright © 1982 by American Physiological Society
On-line cardiac mapping: an analog approach using video and multiplexing techniques
I. Parson, P. Mendler and E. Downar
A video and multiplexing system is described that provides a source of
display in real-time, slow-motion, and stop-frame modes of ventricular
activation. The displayed image, consisting of a matrix of 112 dots, is
arranged to represent a polar projection of the ventricles. The dots
brighten at the time of local cardiac activation, which is sensed by an
electrode array monitoring the myocardium. Experiments in in situ canine
hearts have provided detailed depictions at 8.3-ms intervals of the
ventricular activation sequence during sinus and ventricularly paced
rhythm. The origin of ventricular paced beats can be located with an
accuracy of less than 5 mm. Coronary occlusion produces a defect in the
displayed image that outlines the ischemic area and demonstrates regions of
delayed conduction. This approach to ventricular mapping provides a
detailed on-line display of activation with a recording capacity of 1 h.
The system offers a practical, inexpensive alternative to computerized
methods of investigating ventricular arrhythmias in both the experimental
and intraoperative environment.
