A comparison of biofeedback-assisted cardiodeceleration in type A and B men: modification of stress-associated cardiopulmonary and hemodynamic adjustments.

Abstract

The primary purpose of this experiment was to examine the cardiac effects of instructions and biofeedback to reduce heart rate during both rest and a behavioral stressor. A second purpose was to assess respiratory, hemodynamic, and metabolic function in conjunction with heart rate. A final aim was to compare the effects of biofeedback on Type A and B men. Type A subjects fell in the upper 10% of the distribution of Jenkin's Activity Survey scores and Type B subjects fell in the lower 10%. Subjects experienced one of three instructional sets during an initial session: instructions to reduce heart rate with biofeedback; instructions to reduce heart rate without biofeedback; and instructions to sit quietly. During a second session, all subjects received identical instructions prior to the behavioral stressor. Heart rate, pulmonary gas exchange, and ventilation were measured breath-by-breath. During the first session, the groups did not differ in any measured parameter, but Type As had higher heart rates than did Type Bs across all conditions. During the second session, subjects given instructions to reduce heart rate with and without biofeedback did not differ in heart rate; as expected, however, both of these groups had smaller increases in heart rate than did the control group. Interestingly, the tachycardia of the control group occurred without an increase in oxygen consumption, indicating a cardiac-metabolic dissociation in this group. The modification of heart rate without a concomitant change in metabolism is important in understanding the association between cardiac and metabolic function.

The psychobiology of strained breathing and its cardiovascular implications: A functional system review

“…Indirect evidence for the occurrence of straining may be derived from the effects of respiratory rate and depth on the cardiovascular system~Berger, Grossman, Stemmler, & Meinhart, 1990;Novak et al, 1993;Richter & Spyer, 1990;Saul et al, 1991;Saul, Berger, Chen, & Cohen, 1989!. Such indirect indications suggest that strained breathing may have been performed in many~psycho!physiological experiments, in which the results may support an additional explanatioñ Benson, Herd, Morse, & Kelleher, 1969;Brown, Beightol, Koh, & Eckberg, 1993;Davies & Neilson, 1967;Grossman, 1983;Hansen & Herd, 1982;Herd, Morse, Kelleher, & Jones, 1969;Hirsch & Bishop, 1981;Porges, McCabe, & Yongue, 1982;Ross & Steptoe, 1980;Sgoifo et al, 1994;Sleigh & Henderson, 1995;Somsen, Molen, Boomsma, & Orlebeke, 1985;Sroufe, 1971;Stoney et al, 1987;Suess, Porges, & Plude, 1994!.…”