Circadian heart rate and blood pressure variability considered for research and patient care.
OBJECTIVE
To review mechanisms of circadian variations in heart rate variability (HRV) and blood pressure variability (BPV) and mortality and morbidity due to cardiovascular diseases (CVD).


METHODS
Results from 7-day/24-h HRV and BPV are interpreted by gender and age-specified reference values in the context of a Medline search.


RESULTS
Abnormal HRV and BPV measured around the clock for 7 days provides information on the risk of subsequent morbid events in subjects without obvious heart disease and without abnormality outside the conventional (in the sense of chronobiologically unquantified) physiological range. Meditation, beta-blockers, ACE inhibitors, n-3 fatty acids and estrogens may have a beneficial influence on HRV, but there is no definitive outcome-validated therapy. Low HRV has been associated with a risk of arrhythmias and arrhythmic death, unstable angina, myocardial infarction, progression of heart failure and atherosclerosis. BPV may be characterized by treatable circadian-hyper-amplitude-tension (CHAT), which can be transient '24-h CHAT' or '7-day-CHAT', MESOR-hypertension and/or an unusually-timed (odd) circadian acrophase (ecphasia), all associated with an increased risk of stroke, stroke death, myocardial infarction, and kidney disease.


CONCLUSIONS
Precise insight into the patho-physiology in time of HRV and BPV is needed with development of a consensus on best measures of HRV for clinical purposes and to determine when a 7-day record interpreted chronobiologically suffices and when it does not, for detection within as well as outside the conventional normal range, for diagnostic clinical practice and to direct therapy of risk greater than that associated with hypertension, smoking or any other risk factor.
Singh
Ram B
RB
Medical Hospital and Research Center, Civil Lines, Moradabad, India. icn@mickyonline.com
Cornélissen
Germaine
G
Weydahl
Andi
A
Schwartzkopff
Othild
O
Katinas
George
G
Otsuka
Kuniaki
K
Watanabe
Yoshihiko
Y
Yano
Shoki
S
Mori
Hideki
H
Ichimaru
Yuhei
Y
Mitsutake
Gen
G
Pella
Daniel
D
Fanghong
Lu
L
Zhao
Ziyan
Z
Rao
Reema S
RS
Gvozdjakova
Anna
A
Halberg
Franz
F
D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D018450:Disease Progression; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D012307:Risk Factors