Local and Systemic Cardiovascular Effects from Monochromatic Infrared Therapy in Patients with Knee Osteoarthritis: A Double-Blind, Randomized, Placebo-Controlled Study

Infrared (IR) therapy is used for pain relief in patients with knee osteoarthritis (OA). However, IR’s effects on the cardiovascular system remain uncertain. Therefore, we investigated the local and systemic cardiovascular effects of monochromatic IR therapy on patients with knee OA in a double-blind, randomized, placebo-controlled study. Seventy-one subjects with knee OA received one session of 40 min of active or placebo monochromatic IR treatment (with power output of 6.24 W, wavelength of 890 nm, power density of 34.7 mW/cm2for 40 min, total energy of 41.6 J/cm2per knee per session) over the knee joints. Heart rate, blood pressure, and knee arterial blood flow velocity were periodically assessed at the baseline, during, and after treatment. Data were analyzed by repeated-measure analysis of covariance. Compared to baseline, there were no statistically significant group x time interaction effects between the 2 groups for heart rate (P=0.160), blood pressure (systolic blood pressure:P=0.861; diastolic blood pressure:P=0.757), or mean arterial blood flow velocity (P=0.769) in follow-up assessments. The present study revealed that although there was no increase of knee arterial blood flow velocity, monochromatic IR therapy produced no detrimental systemic cardiovascular effects.

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Diurnal variation in time to presyncope and associated circulatory changes during a controlled orthostatic challenge

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00030.2010 ◽

2010 ◽

Vol 299 (1) ◽

pp. R55-R61 ◽

Cited By ~ 25

Author(s):

N. C. S. Lewis ◽

G. Atkinson ◽

S. J. E. Lucas ◽

E. J. M. Grant ◽

H. Jones ◽

...

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Diurnal Variation ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Cerebral Blood Flow Velocity ◽

Orthostatic Challenge ◽

Arterial Blood ◽

Neurally Mediated Syncope

Epidemiological data indicate that the risk of neurally mediated syncope is substantially higher in the morning. Syncope is precipitated by cerebral hypoperfusion, yet no chronobiological experiment has been undertaken to examine whether the major circulatory factors, which influence perfusion, show diurnal variation during a controlled orthostatic challenge. Therefore, we examined the diurnal variation in orthostatic tolerance and circulatory function measured at baseline and at presyncope. In a repeated-measures experiment, conducted at 0600 and 1600, 17 normotensive volunteers, aged 26 ± 4 yr (mean ± SD), rested supine at baseline and then underwent a 60° head-up tilt with 5-min incremental stages of lower body negative pressure until standardized symptoms of presyncope were apparent. Pretest hydration status was similar at both times of day. Continuous beat-to-beat measurements of cerebral blood flow velocity, blood pressure, heart rate, stroke volume, cardiac output, and end-tidal Pco2 were obtained. At baseline, mean cerebral blood flow velocity was 9 ± 2 cm/s (15%) lower in the morning than the afternoon ( P < 0.0001). The mean time to presyncope was shorter in the morning than in the afternoon (27.2 ± 10.5 min vs. 33.1 ± 7.9 min; 95% CI: 0.4 to 11.4 min, P = 0.01). All measurements made at presyncope did not show diurnal variation ( P > 0.05), but the changes over time (from baseline to presyncope time) in arterial blood pressure, estimated peripheral vascular resistance, and α-index baroreflex sensitivity were greater during the morning tests ( P < 0.05). These data indicate that tolerance to an incremental orthostatic challenge is markedly reduced in the morning due to diurnal variations in the time-based decline in blood pressure and the initial cerebral blood flow velocity “reserve” rather than the circulatory status at eventual presyncope. Such information may be used to help identify individuals who are particularly prone to orthostatic intolerance in the morning.

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Effects of umbilical arterial resistance on its arterial blood ﬂow velocity waveforms

Acta Obstetricia Et Gynecologica Scandinavica ◽

10.1080/j.1600-0412.2001.080004307.x ◽

2001 ◽

Vol 80 (4) ◽

pp. 307-307

Author(s):

Makiko Mine ◽

Junko Nishio ◽

Yuichiro Nakai ◽

Motoharu Imanaka ◽

Sachio Ogita

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Arterial Blood Flow ◽

Arterial Resistance ◽

Arterial Blood

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Suctioning and Cerebral Blood Flow

PEDIATRICS ◽

10.1542/peds.73.5.737a ◽

1984 ◽

Vol 73 (5) ◽

pp. 737-737

Author(s):

JEFFREY M. PERLMAN ◽

JOSEPH J. VOLPE

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Intracranial Pressure ◽

Flow Velocity ◽

Arterial Blood Pressure ◽

Blood Flow Velocity ◽

Cerebral Blood Flow Velocity ◽

Base Line ◽

Arterial Blood

In Reply.— Marshall misread a critical piece of information in the text. His interpretation of the data would be correct, if the intracranial pressure, arterial blood pressure, and cerebral blood flow velocity changes occurred simultaneously. However, as we stated in the text (see section on "Temporal Features of Changes with Suctioning"), the intracranial pressure fell to base-line values immediately following suctioning, whereas the changes in arterial blood pressure and cerebral blood flow velocity occurred more slowly over an approximately two-minute period.

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Cerebral blood flow velocity response to induced and spontaneous sudden changes in arterial blood pressure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.280.5.h2162 ◽

2001 ◽

Vol 280 (5) ◽

pp. H2162-H2174 ◽

Cited By ~ 89

Author(s):

Ronney B. Panerai ◽

Suzanne L. Dawson ◽

Penelope J. Eames ◽

John F. Potter

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Flow Velocity ◽

Arterial Blood Pressure ◽

Blood Flow Velocity ◽

Cerebral Blood Flow Velocity ◽

Step Response ◽

Arterial Blood ◽

Step Responses

The influence of different types of maneuvers that can induce sudden changes of arterial blood pressure (ABP) on the cerebral blood flow velocity (CBFV) response was studied in 56 normal subjects (mean age 62 yr, range 23–80). ABP was recorded in the finger with a Finapres device, and bilateral recordings of CBFV were performed with Doppler ultrasound of the middle cerebral arteries. Recordings were performed at rest (baseline) and during the thigh cuff test, lower body negative pressure, cold pressor test, hand grip, and Valsalva maneuver. From baseline recordings, positive and negative spontaneous transients were also selected. Stability of Pco 2 was monitored with transcutaneous measurements. Dynamic autoregulatory index (ARI), impulse, and step responses were obtained for 1-min segments of data for the eight conditions by fitting a mathematical model to the ABP-CBFV baseline and transient data (Aaslid's model) and by the Wiener-Laguerre moving-average method. Impulse responses were similar for the right- and left-side recordings, and their temporal pattern was not influenced by type of maneuver. Step responses showed a sudden rise at time 0 and then started to fall back to their original level, indicating an active autoregulation. ARI was also independent of the type of maneuver, giving an overall mean of 4.7 ± 2.9 ( n = 602 recordings). Amplitudes of the impulse and step responses, however, were significantly influenced by type of maneuver and were highly correlated with the resistance-area product before the sudden change in ABP ( r = −0.93, P < 0.0004). These results suggest that amplitude of the CBFV step response is sensitive to the point of operation of the instantaneous ABP-CBFV relationship, which can be shifted by different maneuvers. Various degrees of sympathetic nervous system activation resulting from different ABP-stimulating maneuvers were not reflected by CBFV dynamic autoregulatory responses within the physiological range of ABP.

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