Abstract-Sympathetic hyperactivity and parasympathetic withdrawal may cause and sustain hypertension. This autonomic imbalance is in turn related to a reduced or reset arterial baroreflex sensitivity and chemoreflex-induced hyperventilation. Slow breathing at 6 breaths/min increases baroreflex sensitivity and reduces sympathetic activity and chemoreflex activation, suggesting a potentially beneficial effect in hypertension. We tested whether slow breathing was capable of modifying blood pressure in hypertensive and control subjects and improving baroreflex sensitivity. Continuous noninvasive blood pressure, RR interval, respiration, and end-tidal CO 2 (CO 2 -et) were monitored in 20 subjects with essential hypertension (56.4Ϯ1.9 years) and in 26 controls (52.3Ϯ1.4 years) in sitting position during spontaneous breathing and controlled breathing at slower (6/min) and faster (15/min) breathing rate. Baroreflex sensitivity was measured by autoregressive spectral analysis and "alpha angle" method. Key Words: baroreceptors Ⅲ blood pressure Ⅲ heart rate Ⅲ hypertension Ⅲ nervous system, autonomic Ⅲ respiration A utonomic imbalance has a major role in the etiology of hypertension. 1-4 Such imbalance, characterized by an increase in sympathetic activity (with a possible reduction in parasympathetic activity), is present not only in early and borderline hypertension but also contributes to the maintenance of sustained hypertension. 2 Moreover, several cardiovascular risk factors frequently associated with hypertension are etiologically linked to sympathetic activation. 2,5 At least one of the mechanisms associated with this autonomic imbalance is the reduced baroreflex sensitivity. The baroreflex is reduced or reset toward elevated blood pressure values in hypertension, blunting its ability to suppress the increased sympathetic activity. 6 An impairment of the baroreflex has a direct relation to increased 24-hour blood pressure variability, which in turn correlates with the increase in target-organ damage. 7 Furthermore, there are reports indicating a chemoreflex activation in essential hypertension, which can be an additional mechanism responsible for the increase in sympathetic activity. 8 Given the clinical and prognostic value of reducing sympathetic activation and increasing baroreflex sensitivity in hypertension, it is interesting to note that slow breathing at 6 cycles/min increases baroreflex sensitivity in normal subjects and patients with chronic heart failure 9,10 and also reduces muscle nerve sympathetic activity 11 and chemoreflex activation, 12 thus suggesting a potentially beneficial effect in hypertension. However, there is little evidence about the effect of slow breathing on arterial baroreflex in hypertensive patients, although a few recent studies have shown that device-guided breathing exercise may reduce blood pressure in hypertensive patients. 13 This study aims to test whether slow breathing at 6 cycles/min reduces blood pressure in hypertensive and normal subjects, and if this effect is linked to a...

Background-Reactions to music are considered subjective, but previous studies suggested that cardiorespiratory variables increase with faster tempo independent of individual preference. We tested whether compositions characterized by variable emphasis could produce parallel instantaneous cardiovascular/respiratory responses and whether these changes mirrored music profiles. Methods and Results-Twenty-four young healthy subjects, 12 musicians (choristers) and 12 nonmusician control subjects, listened (in random order) to music with vocal (Puccini's "Turandot") or orchestral (Beethoven's 9th Symphony adagio) progressive crescendos, more uniform emphasis (Bach cantata), 10-second period (ie, similar to Mayer waves) rhythmic phrases (Giuseppe Verdi's arias "Va pensiero" and "Libiam nei lieti calici"), or silence while heart rate, respiration, blood pressures, middle cerebral artery flow velocity, and skin vasomotion were recorded. Common responses were recognized by averaging instantaneous cardiorespiratory responses regressed against changes in music profiles and by coherence analysis during rhythmic phrases. Vocal and orchestral crescendos produced significant (Pϭ0.05 or better) correlations between cardiovascular or respiratory signals and music profile, particularly skin vasoconstriction and blood pressures, proportional to crescendo, in contrast to uniform emphasis, which induced skin vasodilation and reduction in blood pressures. Correlations were significant both in individual and group-averaged signals. Phrases at 10-second periods by Verdi entrained the cardiovascular autonomic variables. No qualitative differences in recorded measurements were seen between musicians and nonmusicians. Key Words: blood pressure Ⅲ heart rate Ⅲ ultrasonography, Doppler, transcranial Ⅲ arousal Ⅲ therapy, music T here has been considerable recent interest in the cardiovascular, respiratory, and neurophysiological effects of listening to music, including the brain areas involved, which appear to be similar to those involved in arousal. 1,2 Responses to music appear to be personal, particularly when skin tingling or "chills" occur, 3-5 which suggests individual reactions to music that are dependent on individual preferences, mood, or emotion. However, our previous study 6 showed consistent cardiovascular and respiratory responses to music with different styles (raga/techno/classical) in most subjects, in whom arousal was related to tempo and was associated with faster breathing. The responses were qualitatively similar in musicians and nonmusicians and apparently were not influenced by music preferences, although musicians responded more. That original study concerned average responses to music rather than to dynamic changes during a track, because we used artificial tracks with 2 or 4 minutes of consistent style and tempo. Changes in tempo and emphasis were less evident, which is important for originating "chills." Conclusions-Music Clinical Perspective on p 3180We did not then study the entrainment of spontaneous cardiovascular ...