Season's Appreciations 1998.

We thank all of those who have supported the continuance of chronobiology at the University of Minnesota. Special credit is due to Earl E. Bakken, who introduced the implantable cardiac pacemaker and also the concept of the free-running oscillator, an invaluable device and a fertile concept, respectively. Free-running led to the coining of “circa” rhythms. There may again be a center that does more than the design and/or analysis of work done elsewhere. We have started to try to bring into the mainstream of health care (Halberg F. 1998; Cornélissen et al. 1999) the fruits of an approach that led Erna and Julia (Halberg J. et al. 1980) to the documentation of a murine disease risk syndrome. A very large circadian amplitude of blood pressure (Otsuka 1998) and a very small standard deviation of heart rate (Cornélissen et al. 1999) underlie asymptomatic clinical conditions of high disease risk. One of these risk syndromes is circadian blood pressure overswinging or CHAT, short for circadian hyper-amplitude-tension. Another syndrome, in health (!), is an excessively low variability in heart rate, called CAHRV, for chronome alteration of heart rate variability (Kleiger 1987; Cornélissen et al. 1990; Otsuka et al. 1997). The switch from focus on rehabilitation (after the fact of catastrophic disease) to the lowering of an elevated disease risk in the superficially healthy person—pre-habilitation—became our major concern in 1998, notably for stroke prevention. Locally and in a worldwide cooperation first and foremost, we monitored blood pressures, heart rates and electrocardiograms for spans of not less than 7 days whenever possible. Whenever indicated and for research, individuals monitored themselves for much longer durations. F. Halberg