Blood flow and respiratory rates can synch with music, indicating that music could one day be a therapeutic tool for blood pressure control and rehabilitation, according to a study by Italian researchers published in Circulation: Journal of the American Heart Association.
The researchers found in an earlier study (Heart. 2006 Apr;92(4):445-52) that music with faster tempos resulted in increased breathing, heart rate and blood pressure. When the music was paused, breathing, heart rate and blood pressure decreased, sometimes below the beginning rate. Slower music caused declines in heart rates.
In an extension of those findings, researchers recently discovered swelling crescendos appear to induce moderate arousal while decrescendos induce relaxation. In music, a crescendo is a gradual volume increase, and a decrescendo is a gradual volume decrease.
"Music induces a continuous, dynamic - and to some extent predictable - change in the cardiovascular system," said Luciano Bernardi, M.D., lead researcher of the study and professor of Internal Medicine at Pavia University in Pavia, Italy. "It is not only the emotion that creates the cardiovascular changes, but this study suggests that also the opposite might be possible, that cardiovascular changes may be the substrate for emotions, likely in a bi-directional way."
Researchers studied 24 healthy Caucasians matched for age and sex - 24 to 26 years old with 12 experienced singers (nine women) and 12 participants (seven women) who had no previous musical training. Study participants were fitted with headphones and were attached to electrocardiogram (ECG) and monitors to measure blood pressure, cerebral artery flow, respiration and narrowing of blood vessels on the skin.
Five random tracks of classical music were played - including selections from Beethoven's Ninth Symphony; an aria from Puccini's Turandot; a Bach cantata (BMW 169); Va Pensiero from Nabucco; Libiam Nei Lieti Calici from La Traviata - as well as two minutes of silence.
Researchers found:
- Every crescendo led to increased narrowing of blood vessels under the skin, increased blood pressure and heart rate and increased respiration amplitude. In each music track the extent of the effect was proportional to the change in music profile.
- During the silent pause, changes decreased, with blood vessels under the skin dilating and marked reductions in heart rate and blood pressure. Unlike with music, silence reduced heart rate and other variables, indicating relaxation.
- Music phrases around 10 seconds long, like those used in "Va Pensiero" and "Libiam Nei Lieti Calici," synchronized inherent cardiovascular rhythm, thus modulating cardiovascular control.
"The profile of music (crescendo or decrescendo) is continuously tracked by the cardiovascular and respiratory systems," Bernardi said. "This is particularly evident when music is rich in emphasis, like in operatic music. These findings increase our understanding of how music could be used in rehabilitative medicine."