Carotid Pressure Plethysmograms - Effects of Age Diastolic Blood Pressure Relative Body Weight and Physical Activity *)
Journal/Book: Sonderdruck aus "Archiv für Kreislaufforschung" Band 36 Seite 49-58 1961. 1961;
Abstract: From the Laboratory of Physiological Hygiene University of Minnesota Minneapolis Minnesota (USA) *) Supported in part by research grants from the American Heart Association and the U. S. Public Health Service (Grant H-3088 C 2). Summary 1. In 38 normal young men 135 normal middle-aged railroad clerks 139 normal middle-aged railroad switchmen and 75 normal older men the carotid pulse was recorded from an external pick-up. The following items were me asured: absolute peak times (P) relative peak time (peak time as per cent of cycle length) relative amplitude of the point of the first anacrotic break (a) in per cent of the peak amplitude (b); relative amplitude of the first anacrotic break in per cent of the amplitude of the dicrotic notch (c). 2. The peak times increase with age from a mean of 0.10 seconds at age 23 to a mean of 0.21 seconds at age 60. In the two middle-aged groups the distribution of peak times was bimodal with peak frequencies centering an means of 0.10 and 0.20 seconds. In the older men the distribution of peak times centered an values of about 0.21 seconds. Relative peak times also progressed with age but without a clear bimodal distribution in middle age. 3. Both percentile ratios a/b and a/c decrease with age due to the progressive decrease of the amplitude at which the major anacrotic break (a) occurs and a parallel elevation of the level of the dicrotic notch (c). The mean % a/b at age 23 was 87.2 per cent and at age 60 was 69.8 per cent; the corresponding mean values for a/c were 226.0 and 106.3 per cent respectively. The distribution of values of a/b and a/c in the various age subgroups followed a normal pattern in our sample. 4. The two groups of middle-aged men with different levels of habitual physical activity (switchmen and clerks) exhibited no significant differences in the above pulse items. 5. A single and multiple linear regression analysis was done between the pulse variable a/b with age with diastolic blood pressure and with relative body weight. The relative body weight was not significantly correlated with a/b P or P/C in contrast to the variables of age and diastolic blood pressure both of which were found to have significant predictive value for these pulse items the influence of age being larger than that of diastolic blood pressure. 6. Data obtained with this central pressure plethysmography chow much more intraindividual consistency than similar data obtained from peripheral pulses the consistency of the items a/b and P (consistency coefficient = 0.93 and 0.83) being equal to that of most electrocardiographic items. This method may be useful in studying age trends in entire population surveys in conjunction with electrocardiographic and peripheral vascular data. . . .