Comprehensive multilevel in vivo and in vitro analysis of heart rate fluctuations in mice by ECG telemetry and electrophysiology.

The normal heartbeat slightly fluctuates around a mean value; this phenomenon is called physiological heart rate variability (HRV). It is well known that altered HRV is a risk factor for sudden cardiac death. The availability of genetic mouse models makes it possible to experimentally dissect the mechanism of pathological changes in HRV and its relation to sudden cardiac death.