Measuring Electrocardiogram and Heart Rate in Small Laboratory Animals with Radio-Telemetry

The last few years, several studies have shown that measurements of physiological variables, such as electrocardiogram (ECG) and heart rate (HR) from freely moving rats and mice by using implantable radio-telemetry were more efficient, reliable and less labour intensive when compared to measurement techniques described in the literature so far. Nowadays, measurement of ECG and HR by radio-telemetry has been described and validated for many laboratory animal species, including rats and mice. The implantable radio-telemetry technique can circumvent many of the problems associated with the conventional method (exteriorised catheters) of ECG and HR monitoring in mice and rats. This chapter describes not only the surgical aspects of the radio-telemetry techniques currently used to monitor and measure ECG and HR in awake animals, but also the ECG waveforms in small laboratory animals obtained with this technique.