Circadian Influences on Myocardial Ischemia-Reperfusion Injury and Heart Failure.

The impact of circadian rhythms on cardiovascular function and disease development is well established, with numerous studies in genetically modified animals emphasizing the circadian molecular clock's significance in the pathogenesis and pathophysiology of myocardial ischemia and heart failure progression. However, translational preclinical studies targeting the heart's circadian biology are just now emerging and are leading to the development of a novel field of medicine termed circadian medicine. In this review, we explore circadian molecular mechanisms and novel therapies, including (1) intense light, (2) small molecules modulating the circadian mechanism, and (3) chronotherapies such as cardiovascular drugs and meal timings. These promise significant clinical translation in circadian medicine for cardiovascular disease. (4) Additionally, we address the differential functioning of the circadian mechanism in males versus females, emphasizing the consideration of biological sex, gender, and aging in circadian therapies for cardiovascular disease.

Enhancing circadian rhythms-the circadian MEGA bundle as novel approach to treat critical illness.

Circadian rhythms are essential to physiological homeostasis, but often disrupted in the intensive care unit (ICU) due to the absence of natural zeitgebers and exposure to treatments which affect circadian regulators. This is increasingly recognized as a contributor to morbidity and mortality across a variety of medical conditions including critical illness. Maintenance of circadian rhythms is particularly relevant to critically ill patients, who are restricted not only to the ICU environment but often bed bound. Circadian rhythms have been evaluated in several ICU studies, but effective therapies to maintain, restore, or amplify circadian rhythms have not been fully established yet. Circadian entrainment and circadian amplitude enhancement are integral to patients' overall health and well-being, and likely even more important during response to and recovery from critical illness. In fact, studies have shown that enhancing the amplitude of circadian cycles has significant beneficial effects on health and wellbeing. In this review, we discuss up-to-date literature on novel circadian mechanism that could not only restore but enhance circadian rhythms in critical illness by using a MEGA bundle consisting of intense light therapy each morning, cyclic nutrition support, timed physical therapy, nighttime melatonin administration, morning administration of circadian rhythm amplitude enhancers, cyclic temperature control and a nocturnal sleep hygiene bundle.