Content area
Full Text
BACKGROUND Acute myocardial infarction places additional demands on an already compromised myocardium. Relaxing music can induce a relaxation response, thereby reversing the deleterious effects of the stress response.
OBJECTIVES To compare the effects of relaxing music; quiet, uninterrupted rest; and "treatment as usual" on anxiety levels and physiological indicators of cardiac autonomic function.
METHODS A 3-group repeated measures experimental design was used. Forty-five patients, 15 per group, with acute myocardial infarction were assigned randomly to 20 minutes of (1) music in a quiet, restful environment (experimental group); (2) quiet, restful environment without music (attention); or (3) treatment as usual (control). Anxiety levels and physiological indicators were measured
RESULTS Immediately after the intervention, reductions in heart rate, respiratory rate, and myocardial oxygen demand were significantly greater in the experimental group than in the control
group. The reductions in heart rate and respiratory rate remained significantly greater 1 hour later. Changes in heart rate, respiratory rate, and myocardial oxygen demand in the attention group did not differ significantly from changes in the other 2 groups. The 3 groups did not differ with respect to systolic blood pressure. Increases in high-frequency heart rate variability were significantly greater in the experimental and attention groups than in the control group immediately after the intervention. State anxiety was reduced in the experimental group only; the reduction was significant immediately and 1 hour after the intervention.
CONCLUSIONS Patients recovering from acute myocardial infarction may benefit from music therapy in a quiet, restful environment. (American Journal of Critical Care. 1999;8:220-230)
Each year 1.5 million persons in the United States experience acute myocardial infarction (AMI).1 AMI is accompanied by elevated anxiety levels, which in turn increase activity of the sympathetic nervous system. Compelling evidence indicates a relationship between action of the autonomic nervous system and sudden cardiac death.2-5 Specifically, activation of the parasympathetic division of the autonomic nervous system exerts a protective and antifibrillatory effect on the heart, and increased activity of the sympathetic division contributes to the onset of life-threatening cardiac dysrhythmias. When the activity of the sympathetic nervous system is increased, an additional stress is placed on an already compromised myocardium. This additional stress results in increases in heart rate, blood pressure, and corresponding myocardial oxygen requirements....