TY - JOUR
T1 - Effects of hydrophilic and lipophilic β-blockers on heart rate variability and baroreflex sensitivity in normal subjects
AU - Pitzalis, Maria Vittoria
AU - Mastropasqua, Filippo
AU - Massari, Francesco
AU - Forleo, Cinzia
AU - Passantino, Andrea
AU - Colombo, Roberto
AU - Totaro, Paolo
AU - Rizzon, Paolo
PY - 1998
Y1 - 1998
N2 - To evaluate the effect of a hydrophilic and a lipophilic β-blocker on the autonomic nervous system, 20 normal subjects were studied under baseline conditions and 7 days after being randomly assigned to metoprolol (200 mg/day), nadolol (80 mg/day), and placebo. Under each condition, the time- domain parameters were analyzed by means of 24-hour ECG monitoring and the frequency-domain parameters by means of the autoregressive method using 10- minute ECGs during rest, controlled respiration, and after a head-up tilt test. The alpha index (the gain in the relationship between the BB period and systolic arterial pressure variability) was also calculated. Both nadolol and metoprolol significantly increased all of the time-domain parameters except the standard deviation of the BB intervals; they also modified the frequency- domain parameters. Both blunted the significant reduction in the high frequency (HF) component and alpha index during tilt. In normal subjects, hydrophilic and lipophilic β-blockers similarly modify the time- and frequency-domain parameters that are particularly evident when high sympathetic tone is present (during daytime and tilt). The value of the alpha index was increased by both β-blockers in the HE, but not in the low frequency band; this difference might be due to the fact that the former is a measure of the vagal component of the baroreflex control and the latter a measure of the sympathethic component. The effects of hydrophilic and lipophilic β-blockers on the time- and frequency-domain parameters of heart rate variability are similar.
AB - To evaluate the effect of a hydrophilic and a lipophilic β-blocker on the autonomic nervous system, 20 normal subjects were studied under baseline conditions and 7 days after being randomly assigned to metoprolol (200 mg/day), nadolol (80 mg/day), and placebo. Under each condition, the time- domain parameters were analyzed by means of 24-hour ECG monitoring and the frequency-domain parameters by means of the autoregressive method using 10- minute ECGs during rest, controlled respiration, and after a head-up tilt test. The alpha index (the gain in the relationship between the BB period and systolic arterial pressure variability) was also calculated. Both nadolol and metoprolol significantly increased all of the time-domain parameters except the standard deviation of the BB intervals; they also modified the frequency- domain parameters. Both blunted the significant reduction in the high frequency (HF) component and alpha index during tilt. In normal subjects, hydrophilic and lipophilic β-blockers similarly modify the time- and frequency-domain parameters that are particularly evident when high sympathetic tone is present (during daytime and tilt). The value of the alpha index was increased by both β-blockers in the HE, but not in the low frequency band; this difference might be due to the fact that the former is a measure of the vagal component of the baroreflex control and the latter a measure of the sympathethic component. The effects of hydrophilic and lipophilic β-blockers on the time- and frequency-domain parameters of heart rate variability are similar.
KW - Alpha index
KW - Controlled breathing
KW - Frequency-domain analysis
KW - Head-up tilt test
KW - Metoprolol
KW - Nadolol
KW - Time-domain analysis
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U2 - 10.1111/j.1540-8159.1998.tb00099.x
DO - 10.1111/j.1540-8159.1998.tb00099.x
M3 - Article
C2 - 9558688
AN - SCOPUS:0031955984
VL - 21
SP - 559
EP - 567
JO - PACE - Pacing and Clinical Electrophysiology
JF - PACE - Pacing and Clinical Electrophysiology
SN - 0147-8389
IS - 3
ER -