HEART-RATE VARIATION, AGE, AND BEHAVIOR IN SUBJECTS WITH SENILE DEMENTIA OF ALZHEIMER-TYPE

Minute-by-minute heart rate (HR) recordings over a period of 24 h were obtained once for 30 elderly subjects diagnosed as having senile deme ntia of Alzheimer type (SDAT). Twenty-one of the subjects were studied in a hospital ward setting, and nine were studied in their own homes. Twelve were men and 18 were women. Eleven took some form of sedative medication; 10 took no medication. Thirty-minute mean values were unma sked to take account of the effects of activity and sleep on HR. Resul ts indicate that the masked HR circadian rhythm of SDAT may be more of ten unimodal than that of normal subjects of similar age, and that pha se shift of the endogenous, clock-mediated component of the rhythm (wi th higher HR at night) is to be expected in a proportion of individual s with SDAT.