Abstract. Rhythmic heart rate variability signifies a state of cardiovascular health. Loss of heart rate variability increases mortality and morbidity. Strategies that increase beat-to-beat variability include standard medical interventions such as beta blockers. Relaxation, meditation, and music therapy are non-traditional approaches that have been proposed to improve health. Several studies indicate that these alternative methods decrease heart rate and blood pressure. To date, little is known about the impact of music on the autonomic tone of the heart and heart rate variability. We hypothesize that music improves heart rate variability by decreasing cardiac sympathetic tone. In order to assess the effects of music, we used cardiac electrophysiologic studies (EPS) to acquire the sinus node recovery time (SNRT), sino-atrial conduction time (SACT), and A-A interval (AA) in patients exposed to live harp music in the EP lab. The following are preliminary results of our first three study patients. We observed that following exposure to music, these patients show improvement in SNRT, SACT, and AA compared to baseline measurements. These results suggest that the positive effects of exposure to music on heart rate variability are due to changes in autonomic tone.

Background

The concept of heart rate variability (HRV) has become a major determinant in cardiovascular health and prognosis.¹ Factors that lead to inappropriate activation of the sympathetic nervous system can be expected to adversely affect patient outcome, and factors that augment parasympathetic vagal tone tend to improve outcome. HRV is becoming more recognized as a risk predictor for cardiovascular disease. In one study, low HRV was the single most important predictor of a high risk of sudden death or serious arrhythmia.² The landmark Framingham Heart Study also supported the association between HRV and a decrease in all-cause mortality and cardiac events.^3,4 More recently, the ATRAMI study (Autonomic Tone and Reflexes After Myocardial Infarction) confirmed that both HRV and baroreflex sensitivity were independent predictors of cardiovascular mortality.⁵ Interestingly and more well known is the fact that fetal monitoring for HRV during the peri-partum period demonstrates the overall well being of the fetus.

Music has been reported to decrease heart rate and blood pressure in multiple studies in the neonatal population up to the adult population.^6,7 Specifically, in ventilated patients, music was shown to effectively decrease anxiety, heart rate and respiratory rate.⁸ Music was shown to decrease sedative requirements during surgery under spinal anesthesia.⁹ Within 72 hours of acute myocardial infarction, studies have shown that patients benefit from music therapy in regards to reductions in heart rate, respiratory rate, myocardial oxygen demand,¹⁰ and improvement in overall anxiety.¹¹ After coronary artery bypass graft surgery (CABG), music therapy was shown to improve the relaxation response by reducing anxiety, improving mood, and lowering heart rate and blood pressure.¹²