Transient circadian hyper-amplitude-tension (CHAT) may be intermittent: case reports illustrating gliding spectral windows

Variations in 7-day/24-h circadian pattern of ambulatory blood pressure and heart rate of type 2 diabetes patients

AIMS/INTRODUCTION

Diabetes has profound consequences on the cardiovascular system leading to cardiovascular morbidity and mortality in diabetic patients. Blood pressure (BP) has a characteristic and reproducible circadian pattern, with high values during the day and low values at night. A 7-day timed analysis of BP through ambulatory blood pressure monitoring has been used not only to diagnose day and night dipping patterns of blood pressure, but also to measure day-to-day variability and the circadian hyper-amplitude-tension, a condition in which excessive circadian BP amplitude precedes the chronic established hypertension. Our objective was to assess the 7-day/24-h circadian pattern of BP and heart rate in diabetic patients, as it could be helpful in the diagnosis and prevention of cardiovascular morbidity.

MATERIALS AND METHODS

A total of 50 diabetic patients with type 2 diabetes and 50 non-diabetic participants were recruited for the study. General health records were individually maintained, and 7-day/24-h ambulatory blood pressure monitoring using an ambulatory blood pressure monitor was carried out.

RESULTS

The rhythmic parameters of systolic and diastolic BP, heart rate, double amplitude, acrophase and 3-h fractionated hyperbaric index were found to be significantly high in diabetic patients. A total of 12 participants were diagnosed with circadian hyper-amplitude-tension. These data suggest that diabetic patients have certain variations in the circadian pattern of blood pressure and heart rate, which can result in disturbed vascular events, and thus are at greater risk of cardiovascular morbidity.

CONCLUSION

Seven-day/24-h monitoring might be useful as an early predictive tool in assessing future cardiovascular risk, guiding treatment and management of these patients.

Why continued surveillance? Intermittent blood pressure and heart rate abnormality under treatment

Several opinion leaders have monitored their blood pressure systematically a sufficient number of times a day for chronomic (time structural) analyses, from the time of encountering chronobiology until their death; they set an example for others who also may not wish to base treatment on single spotchecks in a health care office. Such self-measurements, while extremely helpful, were not readily feasible without a noteworthy interruption of activities during waking as well as of sleep. New, relatively unobtrusive instrumentation now makes monitoring possible and cost-effective and will save lives. Illustrative results and problems encountered in an as-one-goes self-survey by GSK, a physician-scientist, are presented herein. Both MESOR-hypertension and CHAT (circadian hyper-amplitude-tension) can be intermittent conditions even under treatment, and treatment is best adjusted based on monitoring, rather than "flying blind".

100 or 30 years after Janeway or Bartter, Healthwatch helps avoid 'flying blind'

Longitudinal records of blood pressure (BP) and heart rate (HR) around the clock for days, weeks, months, years, and even decades obtained by manual self-measurements (during waking) and/or automatically by ambulatory monitoring reveal, in addition to well-known large within-day variation, also considerable day-to-day variability in most people, whether normotensive or hypertensive. As a first step, the circadian rhythm is considered along with gender differences and changes as a function of age to derive time-specified reference values (chronodesms), while reference values accumulate to also account for the circaseptan variation. Chronodesms serve for the interpretation of single measurements and of circadian and other rhythm parameters. Refined diagnoses can thus be obtained, namely MESOR-hypertension when the chronome-adjusted mean value (MESOR) of BP is above the upper limit of acceptability, excessive pulse pressure (EPP) when the difference in MESOR between the systolic (S) and diastolic (D) BP is too large, CHAT (circadian hyper-amplitude tension) when the circadian BP amplitude is excessive, DHRV (decreased heart rate variability) when the standard deviation (SD) of HR is below the acceptable range, and/or ecphasia when the overall high values recurring each day occur at an odd time (a condition also contributing to the risk associated with 'non-dipping'). A non-parametric approach consisting of a computer comparison of the subject's profile with the time-varying limits of acceptability further serves as a guide to optimize the efficacy of any needed treatment by timing its administration (chronotherapy) and selecting a treatment schedule best suited to normalize abnormal patterns in BP and/or HR. The merit of the proposed chronobiological approach to BP screening, diagnosis and therapy (chronotheranostics) is assessed in the light of outcome studies. Elevated risk associated with abnormal patterns of BP and/or HR variability, even when most if not all measurements lie within the range of acceptable values, becomes amenable to treatment as a critical step toward prevention (prehabilitation) to reduce the need for rehabilitation (the latter often after costly surgical intervention).

Stress/strain/life revisited. Quantification by blood pressure chronomics: benetensive, transtensive or maletensive chrono-vasculo-neuro-immuno-modulation

We propose to initiate the automatic self-assessment of wear and tear as "stress and strain" by the time structures of blood pressure (BP) and heart rate (HR), in order to arrive eventually at an individualized timely and timed routine of life and to early preventive intervention as soon as needed. The routine may involve physiological scheduling of physical and mental activities and meals, and if need be of non-drug or drug treatment for stress amplification, e.g., by exercise, and/or strain (not stress) relief by relaxation. In so doing, we recognize the circulation as a pillar and marker of preventive and active neuroimmunomodulation (NIM), suggesting that some concerns of a vasculo- and broader NIM can be quantified by transdisciplinary chronobiology using its cartography--chronomics--of time structures, i.e., chronomes, from chronos = time and nomos = rule. Thus, we are introducing the chronomics of BP, HR and of other variables in the historical context of pioneers who were indispensable to experimental medicine. We build upon their contributions, but we must point out when, in the past, by necessity rather than choice, the giants provided rationalizing truisms that are no substitute for systematic serial data collection and appropriate computer analysis. A time-unspecified spotcheck as a baseline is much better than no measurement, but very often it is not enough, and it is always insufficient when an estimate of variability constitutes the information needed. For dynamic cycles, there are only reference cycles as a routine, although when maps are available, single timed spotchecks can be invaluable. With reference to their historical context, here we rely only upon data which necessity, rather than philosophy, compels us to collect.

Melatonin, refractory hypertension, myocardial ischemia and other challenges in nightly blood pressure lowering

A test of the relative merits of timed melatonin for the treatment of cardiac ischemia as well as hypertension refractory to other drugs is documented against the background of earlier chronobiological studies on blood pressure (BP), disease risks, circadian hyper-amplitude-tension and melatonin effects broadly.