Autonomic cardiovascular control and diastolic dysfunction in hypertensive subjects.
BACKGROUND
Early hypertension is associated with left ventricular diastolic dysfunction due to increased end-diastolic pressure. This increase, through the cardiopulmonary reflexes, can influence autonomic cardiovascular control.


METHODS
We assessed autonomic nervous system modulation of cardiovascular signals by power spectral analysis of RR interval and systolic arterial pressure variabilities in subjects with recently diagnosed hypertension with or without diastolic dysfunction and in normotensive control subjects.


RESULTS
Both hypertensive groups had higher low-frequency (LF) power expressed in normalized units (NUs) than normotensive controls (p < 0.05; p < 0.001) during controlled breathing at rest. The LF spectral index measured after tilt was greater in hypertensive subjects with diastolic dysfunction than in those without (p < 0.05). LF NUs measured at rest correlated significantly with the E/A wave ratio and after tilt with the E-wave deceleration time.


CONCLUSIONS
These results seem to indicate that in subjects with recently diagnosed hypertension sympathetic modulation of the sinus node prevails. During tilt, a maneuver designed to stimulate systemic arterial and cardiopulmonary baroreceptor reflexes, hypertensive subjects with diastolic dysfunction, who presumably also have higher end-diastolic pressures, seem to have greater sympathetic modulation of the sinus node than hypertensive subjects without diastolic dysfunction.
Piccirillo
Gianfranco
G
Dipartimento di Scienze dell'Invecchiamento, Policlinico Umberto I, Università La Sapienza, Rome, Italy. gianfranco.piccirillo@uniroma1.it
Germanò
Giuseppe
G
Vitarelli
Antonio
A
Ragazzo
Maddalena
M
di Carlo
Silvia
S
De Laurentis
Tiziana
T
Torrini
Alessia
A
Matera
Sabrina
S
Magnanti
Marzia
M
Marchitto
Nicola
N
Bonanni
Livia
L
Magrì
Damiano
D
D001341:Autonomic Nervous System / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D003971:Diastole / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012119:Respiration; D012146:Rest / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D018667:Tilt-Table Test; D013997:Time Factors