Plexo-serial linear-nonlinear rhythmometry of blood pressure, pulse and motor activity by a couple in their sixties.
A Nippon-Colin (model BP-203X) instrument was used for longitudinal monitoring of systolic and diastolic blood pressure and pulse, at 10-min or other intervals for 26 days and for a shorter span, by a healthy woman, 60 years of age, and her husband, 61 years of age, both following their usual routine in an academic setting and at home. Due to the quasi-portable nature of the instrument, it was possible on most mornings to bring it from the home by car to the laboratory at the University and to return it to the home on most evenings, for about 2 months. The sturdy instrument withstood transportation and functioned flawlessly for the spans investigated. While the lack of true portability is definitely a handicap of the instrument which precludes it from use in sports and during ambulation, the circumstance that measurements during certain excessive activities away from a given site are not feasible can lead to a more standardized assessment of the blood pressure profile in subjects who pursue sedentary occupations. The procedures of linear-nonlinear rhythmometry applied to the data from the woman covering 26-day spans each and her husband covering 3 days, partly at 10-min and 3-min intervals, respectively, reveal the feasibility of quantifying parameters of circadian rhythmicity rather consistently. Spans as short as 48-h, invariably for the case of systolic blood pressure and usually for the case of diastolic blood pressure, though with lesser consistency for heart rate, sufficed to assess the circadian rhythmic component of this couple in their sixties and may constitute an individualized reference standard for blood pressure monitoring by the elderly with a view of assessing blood pressure rhythm alteration before it may become pathogenetic.