Left ventricular mass and heart rate variability in middle-aged and elderly salt-sensitive hypertensive subjects.
Previous reports have shown that in salt-sensitive hypertension a high dietary salt intake can increase sympathetic activity. We evaluated the influence of the autonomic nervous system on myocardial hypertrophy by power spectral analysis of heart rate variability in middle-aged and elderly salt-sensitive hypertensive subjects. We compared autonomic nervous system activity in 32 salt-sensitive hypertensive patients (15 subjects with mean age, 42.4+/-2.4 years and 17 subjects with mean age, 74.6+/-1.6 years) and 20 age-matched normotensive controls. Power spectral analysis detects four spectral components: total power (TP), high-frequency (HF), low-frequency (LF) and very-low-frequency (VLF) power. In the elderly subjects we found an association between the left ventricular mass index (LVMI) and the following variables: very-low frequency (P<0.0001), 24-h urinary sodium excretion (P<0.0001) and diastolic blood pressure (DBP) (P<0.0001). In contrast, in middle-aged subjects we found a significant association between the LVMI and LF (P<0.001). In middle-aged, but not in elderly salt-sensitive hypertensive subjects, increased sympathetic activity correlated with the LVMI (P<0.0001). Our findings suggest an association between sympathetic hyperactivity and the LVMI in middle-aged subjects with salt-sensitive hypertension.
Piccirillo
G
G
I Clinica Medica, Policlinico Umberto I, Università La Sapienza, 00161 Rome, Italy. piccirillog@uniroma1.it
Bucca
C
C
Tarantini
S
S
Santagada
E
E
Viola
E
E
Durante
M
M
Raganato
P
P
Mariano
A
A
Cacciafesta
M
M
Marigliano
V
V