Heart Rate Variability

 

In a healthy state, the heart rate exhibits beat-to-beat variability which is mostly regulated by the inputs from the autonomic nervous system, whereas beat-to-beat variations in heart rate can be quantified by using the heart rate variability (HRV). We analyze HRV to evaluate analysis using performed ECG recordings in rodents. The time domain measurements of power spectral density indices quantify the amount of variability in measurements of the interbeat interval, thereby, it reflects the dynamics of autonomic signaling.

We record ECG in,

1. Anesthetized, and

2. Freely-moving conscious rodents

Recording ECG in freely-moving animals enables us to perform multi session sampling for monitoring chronic changes, whereas recording in anesthetized animals is useful for investigation of the acute changes occurred in response to a specific stimulus such as an applied drug, stress model or visceral distension. In such approach, the HRV parameters (LF, HF and LF: HF) calculated from ECG recordings are expressed as the percentage change values compared to the pre-application period.

                                                             

Figure.1 represents simultaneous recording of ECG and gastric motility in an anesthetized rat.

 

      

Figure.2 & 3 represent obtained ECG and gastric motility recording with time scale set to 20 sec and 1 sec, respectively.