CARDIOVASCULAR REACTIVITY IN TYPE-A AND TYPE-B MALES TO MENTAL ARITHMETIC AND AEROBIC EXERCISE AT AN EQUIVALENT OXYGEN-UPTAKE

Cardiovascular hyperreactivity (i.e., response in excess of metabolic requirements) to psychological stress has been implicated in the development of coronary heart disease. The purpose of this study was to evaluate cardiovascular hyperreactivity to psychological stress in Type A and B subjects. Fifteen Type A and 15 Type B young men performed mental arithmetic and cycle ergometry tasks. Linear regressions were calculated for each dependent variable during exercise with oxygen uptake serving as the independent variable. All cardiovascular variables were significantly correlated (p < .0001) with oxygen uptake during exercise. The regression equations obtained during exercise were then used to predict the value of each cardiovascular variable at the oxygen uptake level obtained during mental arithmetic for each person. Repeated measures ANOVA compared responses observed during arithmetic with responses predicted from exercise at an equivalent oxygen uptake in Type A and B subjects. Heart rate, total peripheral resistance, and mean arterial pressure were significantly greater (p < .0001) and stroke volume was significantly lower (p < .0002) during arithmetic than during exercise, while Heather index, cardiac output, and arteriovenous oxygen difference did not differ significantly. No significant differences were found between Type A and B males. Results demonstrated that cardiovascular hyperreactivity was equally robust across Type A and B subjects.