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Voluntary control of vascular tone by using skin-temperature biofeedback-relaxation in patients with advanced heart
Background:
Advanced heart failure is characterized by activation of the sympathetic nervous system and intense vasoconstriction. Biofeedback-relaxation techniques have been used successfully to treat conditions with similar pathophysiological features.
Objectives:
The purpose of this study was to determine if conscious control of skin temperature via a biofeedback-relaxation technique could produce vasodilation and alter central hemodynamic status and circulating levels of catecholamines in patients with heart failure.
Methods:
Forty patients with advanced heart failure were randomly assigned to either an intervention or a control group. The study was done in a special cardiac step-down unit accepting patients for hemodynamic monitoring. The patients in the intervention group had one session of skin-temperature biofeedback augmented by imagery of hand warmth and modified progressive muscle relaxation. Skin temperature, systemic vascular resistance, cardiac output, plasma levels of norepinephrine and epinephrine, oxygen consumption, respiratory rate, and pulmonary wedge pressure were measured before and after the biofeedback session. Control patients had the same measurements made but were not given instruction in biofeedback-relaxation techniques.
Results:
Patients in the biofeedback-relaxation and control groups had comparable clinical profiles at baseline. Patients undergoing biofeedback-relaxation showed the following changes: (1) increase in skin temperature of 3.1 +/- 2.8 degrees F (1.7 +/- 1.5 degrees C) in the finger and 1.5 +/- 5.2 degrees F (0.4 +/- 1.2 degrees C) in the foot, (2) increase in cardiac output of 0.30 +/- 0.33 L/min, (3) decrease in systemic vascular resistance of 152 +/- 225 dyne.sec.cm-5, and (4) decrease in respiratory rate of 4.5 +/- 3.2 breaths per minute. The biofeedback group exhibited no changes in catecholamine levels or oxygen consumption. No changes in any of these parameters were seen in the control group.
Discussion:
Despite the presence of marked vasoconstriction in patients with advanced heart failure, a single session of biofeedback-relaxation can increase finger temperature and cardiac output and decrease systemic vascular resistance and respiratory rate, apparently without effect on systemic levels of catecholamines or oxygen consumption.