The circulation time in the aged

The arm to tongue circulation time was determined with magnesium sulfate in an epidemiologic examination of 202 men and 305 women over 60 years of age (mean age 70.6 years). There was a significant difference between the average circulation time of men (16.5 ± 4.0 seconds) and women (13.3 ± 2.9 seconds). An increase of the mean circulation time of 1 second per decade of age was demonstrated. The normal lower limit for aged people is 10 seconds for men and 8 seconds for women, and the upper limit is 21 seconds for men and 19 seconds for women. Several factors, both cardiac and extrinsic, determine the circulation time. There was a significant correlation between the circulation time and various indexes, among which the diameter of the heart (r = +0.36), heart rate (r = −0.37) and body height (r = +0.37) seemed to be the most important. By multiple regression analysis 3 percent of the individual variations in circulation time could be explained. These large individual variations and sex differences have to be borne in mind in using the arm to tongue circulation time as a diagnostic test.