Music and the Cardiovascular Response

Interview by Jodie Elrod
Interview by Jodie Elrod
In this feature, Dr. Luciano Bernardi discusses his recent research on the effect of music on cardiovascular rhythms. His research was published in Circulation.1 Tell us about your previous research in this area. How is this current study different? We have been interested for some time in the mechanisms controlling blood pressure and respiration. During such experiments and studies, we came across the effect of rhythmic phrases on the cardiovascular and respiratory systems. We found that rhythmic phrases (e.g., the rosary prayer, mantras) can modify respiration and blood pressure at the rhythm of the phrase at 6 cycles/minute (10-second period). Because the rhythm of the prayer was identical to that of spontaneous cardiovascular oscillations resulting from the sympathetic modulation of the cardiovascular system (so-called Mayer waves), we found an external way of modulating the cardiovacular system (i.e., by reciting rhythmic phrases). The result of this modulation was a reduction in sympathetic activity, an increase in parasympathetic activity and an increase in baroreflex sensitivity. These modifications are to be considered as potentially useful; a predominant/exaggerated sympathetic activity or a low baroreflex sensitivity are considered poor prognostic indices. In our previous research2 we had found that passive listening to music can also modify the cardiovascular/respiratory systems. This occurred mostly by effect of tempo: faster tempi can increase blood pressure/ventilation, while slower tempi, particularly a silent pause when inserted between two music tracks, can obtain the opposite effect. Thus, in this new research, we tried to determine whether listening to music with special rhyhms or emphasis could cause a direct continuous and predictable effect on listeners (with or without musical training). What types of music were used in this study? Why were these specific musical pieces chosen? What was significant or different about each of them? We chose music with a special emphasis (i.e., crescendo and decrescendo), such as the famous arias from Italian opera (“Nessun dorma” from Puccini’s Turandot) or orchestra (adagio from Beethoven’s Ninth Symphony), and contrasted that with music with more stable profiles (e.g., Bach’s Cantata BWV 169, “Gott soll allein mein Herze haben”), and also music with a rhythm identical to that of the Mayer waves of the cardiovascular system (particularly frequent in arias by Verdi: “Va pensiero” from Nabucco, and “Libiamo Ne’ Lieti Calici” from La Traviata) to see whether cardiovascular/respiratory autonomic modulation were directly influenced by music. What cardiovascular and respiratory variables were measured in the patient population? Continuous blood pressure, heart rate, respiration carbon dioxide and ventilation, cerebral circulation, and skin vasomotion were all measured. What were the novel findings shown in this study? Why was it important to include both musicians and non-musicians in this research? We found that listening to these chosen music tracks induced predictable changes both in the cardiovascular and respiratory systems. We could identify precise modifications following the music profile of the tracks presented. Furthermore, the music by Verdi entrained the spontaneous cardiovascular fluctuations at the rhythm of the musical phrase. This type of response was present in all subjects (with obvious individual differences) and with only minor differences with respect to previous musical training. However, musicians (choristers) responded slightly better than non-musicians in terms of respiratory entrainment of music. We were also surprised to note that the effect was totally independent from the musical preference of the subjects. Therefore, music has a profound effect on cardiovascular and respiratory changes. Whatever we are listening to, whether we like the music or not, will to some extent influence our cardiovascular and respiratory systems. We also suggested that this continuous tracking of music in the cardiovascular system may not be the result of emotions (in fact, the subjects did not report strong emotions), but may be one way to actively influence emotions, perhaps through subconscious perceptions of cardiovascular/respiratory modifications. What musical piece had the most significant physiological effect on study participants? Which song made the least physiological impact? All the music, in one sense or another, produced very effective results, although the results were different: the more emphatic music induced arousal, whereas the more “stable” music profile (Bach) induced a general trend of relaxation. Why are “chills” in response to music considered significant? In addition, what effect did musical crescendos have on cardiovascular variables? We did not observe chills in our subjects, so the subjective psychological reactions were minor. Instead, we observed a continuous modulation of the cardiovscular/respiratory system in relation to the music profile: crescendos progressively increased blood pressure, heart rate, and ventilation, while decrescendos did the opposite. There were clear linear relations between the profile of these changes and the profile of the music, supporting our idea. How might this information be valuable to those in the cardiac field? These findings indicate how music can modify the cardiovascular system. There are several myths or dogmas, such as “music works only (or much better) if you like it,” or “music is relaxing,” and so on. We proved that this is only partly true. In fact, music has an effect that, independent from previous training or personal preference, has an effect on its own. We demonstrated that the effects on the cardiovascular/respiratory system can be varied according to the type of music we select. The conclusion of our study supports the use of music in various areas. We think that an interesting area of research and possible application could be the rehabilitation of post-stroke patients, even when the level of consciousness is depressed, suggesting a possible alternative way to stimulate the brain by somatic sensations.