W19-012 Refining a Method to Measure Heart Rate Variability (HRV) in Freely Moving Cats to Assess Welfare (A Winn Feline/EveryCat Health Foundation-funded Study Final Report Summary)
Principal Investigator: Lynette Hart: University of California-Davis
This study was designed as a pilot study to investigate the feasibility of a modified commercial heart rate monitor to determine heart rate variability (HRV), and to compare this with a commercial Holter monitor.
The author’s hypothesis was that the two methods of obtaining HRV data would prove comparable and that the Heart Rate Monitor would be an effective tool for measuring HRV.
Cats in shelters and other situations can be exposed to high levels of stress which can be difficult to quantify. One method of stress quantification is Heart Rate Variability (HRV) which measures the difference in times between heartbeats. Humans and animals under stress have a lower HRV. This may, therefore, represent a feasible method for stress determination of free-ranging animals, assuming it can accurately be measured.
Holter monitors are portable, wearable ECGs designed to monitor many electrocardiographic parameters in free-ranging cats. These accurately report HRV, however, are specialized, large, and expensive. The Polar H10 heart rate sensor is an inexpensive monitor designed for humans that can also report HRV.
In this study, 8 cats were fitted with each monitor under light sedation and their outputs were compared. Of the 8, only a subset of cats had full data from both monitors available for analysis. There was no strong or consistent agreement detected between both machines in regard to HRV.
Despite significant delays due to the COVIF-19 pandemic, the project has now been completed. Data has been collected and analyzed, and manuscript preparation is underway.
The authors ultimately concluded that there is poor agreement between the Holter and Heart Rate Monitor systems and that this specific system cannot be recommended for use in cats. The authors are planning on further analysis of the data using different software methods to determine if there are improvements to the data that can be attained. They also plan to investigate other methods of measurement of heart rate variability.
Further areas for investigation may need to be considered, including the effect of wearing the monitor on feline stress levels, whether the differences in results between machines affect categorization, and investigation of other methods of measurement of HRV.