Effect of intermittent subdiastolic pressure in thigh cuffs on human arterial baroreflex.
BACKGROUND
We investigated the effects of subdiastolic variations of the pressure inside the thigh cuffs on cardiovascular oscillations and arterial baroreflex sensitivity in humans.


METHODS
During 10 min of controlled breathing at low (0.1 Hz) and high (0.25 Hz) frequencies, 30 healthy subjects underwent variations of the pressure inside the thigh cuffs (from 0 to 40 mmHg) at 0.25 and 0.1 Hz respectively; the periods of controlled breathing without cuff pressure modulation were used as a control. The frequency responses of cardiovascular signals were assessed using spectral analysis, and baroreflex sensitivity by the sequence method.


RESULTS
Cuff pressure modulation at 0.25 Hz did not affect the RR interval, arterial pressure, or baroreflex sensitivity; at 0.1 Hz it did not change the RR interval and arterial pressure, but engaged (0.76 +/- 0.2 of coherence) and increased the low frequency oscillations of the RR interval (from 5.6 +/- 1 to 6.1 +/- 0.9 ln ms2, p < 0.05) and improved baroreflex sensitivity by 25% (from 14.2 +/- 9 to 17.7 +/- 10 ms/mmHg, p < 0.01).


CONCLUSIONS
Subdiastolic thigh cuff pressure modulation at 0.1 Hz improved the low frequency oscillations of heart rate and baroreflex sensitivity. This approach represents a new and simple non-pharmacological strategy for acutely improving baroreflex sensitivity in humans.
Massari
F
F
Division of Cardiology, Salvatore Maugeri Foundation, IRCCS, Cassano Murge (BA), Italy.
Forleo
C
C
Colombo
R
R
Campanella
C
C
Mastropasqua
F
F
Rizzon
P
P
Pitzalis
M V
MV
D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods*; D003971:Diastole / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male