Measurement of heart rate and QT interval in the conscious mouse

GF Mitchell, A Jeron, G Koren - American Journal of …, 1998 - journals.physiology.org
GF Mitchell, A Jeron, G Koren
American Journal of Physiology-Heart and Circulatory Physiology, 1998journals.physiology.org
Transgenic mouse models provided a powerful tool to evaluate the physiological
significance of altered quantities or characteristics of specific gene products, such as cardiac
ion channels. We have developed a system to record and analyze changes in the
electrocardiogram in the mouse using an implantable telemetry system. The RR and QT
intervals were measured on individual beats and on signal-averaged complexes derived
from 1, 2, or 4 s of contiguous data each hour during a 24-h period in three male and three …
Transgenic mouse models provided a powerful tool to evaluate the physiological significance of altered quantities or characteristics of specific gene products, such as cardiac ion channels. We have developed a system to record and analyze changes in the electrocardiogram in the mouse using an implantable telemetry system. The R-R and Q-T intervals were measured on individual beats and on signal-averaged complexes derived from 1, 2, or 4 s of contiguous data each hour during a 24-h period in three male and three female FVB mice. Duration of averaging had minimal effect on the measured Q-T. The Q-T interval was shown to be related to the square root of the R-R interval, and an appropriate formula for a rate-corrected Q-T interval (Q-Tc) was derived. Ketamine anesthesia was shown to markedly increase duration and variability in R-R, Q-T, and Q-Tc intervals. In conscious animals, variability in Q-T was low across animals and over time, suggesting that this should be a sensitive model for detection of changes in the Q-T interval in transgenic mice with ion channel defects.
American Physiological Society