Doctoral Dissertations

Date of Award

12-1982

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Psychology

Major Professor

Kathleen A. Lawer

Committee Members

James Lawler, John Malone, Donald Wheeler

Abstract

Two areas of interest for psychophysiological research, the Type A (Coronary-prone) behavior pattern and parental history of hypertension, have been shown to be risk factors for later development of coronary heart disease and high blood pressure, respectively. While these two risk factors may have much different origins since one is a behavioral risk and the other a genetic risk, there nonetheless has been a prevalent notion that individuals with either risk factor present may develop the respective cardiovascular problem as a result of exaggerated cardio vascular reactivity in certain "stressful" situations. More specifically, increased beta-adrenergic (sympathetic influence on the heart) reactivity in these situations has been postulated as being a possible avenue for pathology to occur.

To further investigate these questions, sixty-four male undergrad uate students were given four tasks that were expected to produce different patterns of cardiovascular dynamics: 1) a reading comprehen sion task, 2) a backwards digit span task, 3) a cold pressor task for 75 seconds, and 4) an isometric handgrip task. Blood pressure, heart rate (HR), and a pulse transit time measure (R-wave to pulse peak at the ear) (RPI) were measured. The latter measure was included to more directly assess sympathetic nervous system influences on the heart. The subjects were given the Structured Interview (SI) and the Jenkins Activity Survey (JAS) to classify individuals with the Type A behavior pattern, and a family health history to assess the incidence of parental history of hypertension.

Subjects were classified as either Type A or V vi Type B (not exhibiting the behavior pattern) for the coronary-prone behavior pattern, and positive family history (PFH) or negative family history (NFH) for parental history of hypertension. Although not expected, there were many instances of Type and Family History interacting, especially when the JAS was used as the Type A classification. Type A-PFH subjects were higher than A-NFH subjects on diastolic blood pressure (DBP) and systolic blood pressure (SBP) levels on almost all of the tasks. Interestingly, B-NFH subjects were often higher than B-PFH subjects on blood pressure levels. PFH subjects as a whole showed greater reactivity than NFH subjects on the two psycho logical tasks (Reading Comprehension and Digit Span) with HR and RPI, measures that could reflect greater changes in cardiac output due to increased sympathetic influence on the heart, as well as greater diastolic levels and changes to the two physical tasks (Cold Pressor and Handgrip). This last result could also point to an exaggerated vascular response in offspring of hypertensive parents. These results are discussed along with possible reasons for the lack of Type A-B main effects. Finally, the utility of the RPI measure in certain individual-environment inter actions is discussed.

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