Evaluation of morning blood pressure elevation and autonomic nervous activity in hypertensive patients using wavelet transform of heart rate variability.
To evaluate morning autonomic nervous activity and blood pressure profiles in hypertensive patients by analyzing heart rate variability and ambulatory blood pressure. Data from 82 patients with untreated essential hypertension were analyzed. We evaluated the 24-h profile of blood pressure and that of indices of autonomic nervous activity, i.e., the high frequency component (HF) and low frequency component/HF (LF/HF), which were obtained by wavelet transform of heart rate variability. Patients were classified by dipping status (nondippers, n=28; dippers, n=32; extreme-dippers, n=8; and risers, n=14) and morning blood pressure profile (large, n=9; small, n=60; and inverted, n=13). Nocturnal systolic blood pressure in extreme-dippers was significantly lower than that in the other groups; that in the risers was significantly higher (p<0.05). There were no significant group differences in daytime systolic blood pressure. Daytime and 24-h HF levels were significantly higher in the dipper vs. the riser group (p<0.05). Morning blood pressure elevation negatively correlated to preawake (p<0.01) and nocturnal blood pressure (p<0.05), but not to daytime and post-awake blood pressure. The preawake/postawake ratio of systolic blood pressure positively correlated to that of LF/HF (p<0.01) and negatively correlated to preawake HF levels (p<0.05). Multivariate regression analysis revealed that preawake HF levels (p=0.037) and preawake/postawake ratio of LF/HF (p=0.033) were independently correlated with morning blood pressure elevation ratio. Our results suggest that activation of HF before waking and LF/HF during waking might play an important role in the development of morning blood pressure elevation.
Takagi
Takashi
T
Department of Geriatric Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
Ohishi
Mitsuru
M
Ito
Norihisa
N
Kaibe
Masaharu
M
Tatara
Yuji
Y
Terai
Minako
M
Shiota
Atsushi
A
Hayashi
Norihiro
N
Rakugi
Hiromi
H
Ogihara
Toshio
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged