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

Abstract

Background: 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 treat-ment 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 physi-ological adjunct information to psychiatric assessment and the monitoring of patient response to treatment.