Variations in circadian heart rate in psychiatric disorders: theoretical and practical implications

HG Stampfer,1 SB Dimmitt2 1School of Psychiatry and Clinical Neurosciences, University of Western Australia, 2School of Medicine and Pharmacology, University of Western Australia, Crawley, WA, AustraliaBackground: Data are presented to demonstrate dimensions of variation in circadian heart rate in patients under treatment for a psychiatric disorder and to comment on their clinical relevance.Method: Serial recordings of 24-hour heart rates were obtained from individuals under treatment for a psychiatric disorder and from healthy volunteers.Results: The mean 24-hour heart rate can vary independently of the circadian rate pattern or “rate architecture.” Sleep and waking heart rate can vary independently. Variations in circadian heart rate are state-dependent: broadly different clinical states are associated with distinctly different patterns of circadian heart rate, particularly during sleep.Conclusion: Different regulatory mechanisms or pathways are involved in mediating different aspects of circadian heart rate. An analysis of circadian heart rate can contribute useful physiological adjunct information to psychiatric assessment and the monitoring of patient response to treatment.Keywords: anxiety, depression, neuroendocrine regulation