Journal of Applied Physiology, Vol 41, Issue 5 784-789, Copyright © 1976 by American Physiological Society
New device for automatic recording and processing AV transmission intervals of the heart
S. Akiyama, T. Oshima, Y. Saito and K. Matsuda
The principle and construction of a device made for the purpose of
displaying the interrelationship between two sets of cardiac intervals is
described. Electrical signals derived from the atrium and ventricle of the
experimental animal are fed to the input of the device where a special
switch and an integrated circuit logic gate select the two sets of cardiac
intervals to be measured, e.g., AA and VV or AA and AV intervals. These
intervals are converted into electrical square pulses having voltages
proportional to the respective intervals. Besides simply comparing the two
cardiac intervals by recording them simultaneously against time, the
interrelationship of the two is displayed in an X-Y configuration on-line
on a cathode-ray oscilloscope. This latter method, if used only for the
occasionally induced premature excitations with varied coupling time,
facilitates the measurement of the functional refractory periods for
atrioventricular conduction. The mode of operation of the device is
presented with examples of experiments.
