The ECG is routinely used in many species to monitor effects of drugs. While it is relatively
easy to measure both PR and QRS, measurement of QT is complicated by the fact that this
interval can change with heart rate. In order to compensate for variations in QT due to
variations in heart rate, various correction factors have been used, including those of Bazett
and Hodges. Such corrections were devised for humans and may have limited applicability
in other species. We have systematically varied heart rate in anesthetized rats, guinea pigs …