Abstract:
Background: Atrial Fibrillation (AF) is the most common heart rhythm disorder in clinical practice with prevalence increasing with age. Management of ventricular rate is a key aim of treatment. AF represents a significant burden to both patients and the health care system. The aim of this thesis was to determine the validity of a novel sensing system for monitoring rate control in adults with AF. Methods: The research was conducted in three phases. The BioHarness (Zephyr Technology Corporation) sensing system was validated against two reference standards (Holter monitor and a haemodynamic monitoring system) for measuring heart rate in the first two phases. Phase I was conducted for 10 healthy participants and seven with AF; and Phase II for six participants. Accuracy of heart rates measured and detection times were analysed. An algorithm was developed in Phase III to utilise other physiological data measured by BioHarness device. Heart rate and acceleration data were analysed to visually display a summary of a patient’s rate control using a Microsoft Access database. Results: Overall the BioHarness demonstrated very good reliability against reference standards. There was also good agreement between the Holter monitor and BioHarness device for measuring heart rate for people with sinus rhythm (healthy) and AF. Limits of agreement were -5.68 and 5.52 (mean bias = -0.08 bpm) for healthy participants and -24.22 and 20.36 (mean bias = -1.93 bpm) for people with AF. Limits of agreement between the haemodynamic monitoring system (EP WorkMate, St. Jude Medical) were -18.25 and 17.77 (mean bias = -0.24 bpm). The BioHarness on average detected heart rates less than reference standards for participants in sinus rhythm and AF. The BioHarness also detected heart beats 2.53 ± 0.26 (one standard deviation) seconds later than EP WorkMate. An algorithm was developed to summarise heart rate and acceleration data and reported on adequacy of rate control. Conclusion: The BioHarness device demonstrated very good reliability and validity for measuring heart rate compared to reference standards. It is feasible to integrate physiological data and develop an algorithm for assessing ventricular rate control for people with AF. This BioHarness/smart phone application fits that purpose and a clinical trial is required to determine its utility for aiding the management of AF.