TY - JOUR
T1 - Circadian variation of spectral indices of heart rate variability after myocardial infarction
AU - Lombardi, Federico
AU - Sandrone, Giulia
AU - Mortara, Andrea
AU - La Rovere, Maria Teresa
AU - Colombo, Ettore
AU - Guzzetti, Stefano
AU - Malliani, Alberto
PY - 1992
Y1 - 1992
N2 - The circadian variations of spectral indices of heart rate variability were analyzed in 20 patients 4 weeks after a first and uncomplicated myocardial infarction (MI) and in 20 control subjects. R-R interval and variance showed a characteristic day-night pattern with a significant reduction of the latter parameter in patients after MI (10967 ± 1109 msec2 vs 16860 ± 2132 msec2). Control subjects were characterized by a predominance of low-frequency (∼0.1 Hz) component during the day and of high-frequency (∼0.25 Hz) component during the night, which reflected the expected 24-hour pattern of variation of sympathovagal balance. A 24-hour elevation (64 ± 3 normalized units [nu] vs 56 ± 2 nu; p <0.05) of the low-frequency component and a smaller (23 ± 2 nu vs 32 ± 2 nu; p <0.05) high-frequency component during the night differentiated patients after MI from subjects. The difference between the two groups was even more evident when the 24-hour sympathovagal balance was assessed with the low frequency/high frequency ratio. Thus spectral analysis of heart rate variability indicates that in patients after MI there is an alteration of neural control mechanisms as indicated by the presence of signs of sympathetic activation and by the attenuation of the nocturnal increase in vagal tone.
AB - The circadian variations of spectral indices of heart rate variability were analyzed in 20 patients 4 weeks after a first and uncomplicated myocardial infarction (MI) and in 20 control subjects. R-R interval and variance showed a characteristic day-night pattern with a significant reduction of the latter parameter in patients after MI (10967 ± 1109 msec2 vs 16860 ± 2132 msec2). Control subjects were characterized by a predominance of low-frequency (∼0.1 Hz) component during the day and of high-frequency (∼0.25 Hz) component during the night, which reflected the expected 24-hour pattern of variation of sympathovagal balance. A 24-hour elevation (64 ± 3 normalized units [nu] vs 56 ± 2 nu; p <0.05) of the low-frequency component and a smaller (23 ± 2 nu vs 32 ± 2 nu; p <0.05) high-frequency component during the night differentiated patients after MI from subjects. The difference between the two groups was even more evident when the 24-hour sympathovagal balance was assessed with the low frequency/high frequency ratio. Thus spectral analysis of heart rate variability indicates that in patients after MI there is an alteration of neural control mechanisms as indicated by the presence of signs of sympathetic activation and by the attenuation of the nocturnal increase in vagal tone.
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U2 - 10.1016/0002-8703(92)90804-5
DO - 10.1016/0002-8703(92)90804-5
M3 - Article
C2 - 1595531
AN - SCOPUS:0026633073
VL - 123
SP - 1521
EP - 1529
JO - American Heart Journal
JF - American Heart Journal
SN - 0002-8703
IS - 6
ER -