TY - JOUR
T1 - Heart rate variability patterns before ventricular tachycardia onset in patients with an implantable cardioverter defibrillator
AU - Lombardi, Federico
AU - Porta, Alberto
AU - Marzegalli, Maurizio
AU - Favale, Stefano
AU - Santini, Massimo
AU - Vincenti, Antonello
AU - De Rosa, Angelo
PY - 2000/11/1
Y1 - 2000/11/1
N2 - Time- and frequency-domain analysis of heart rate variability (HRV) has been proven effective in describing alteration of autonomic control mechanisms and in identifying patients with increased cardiac and arrhythmic mortality. Patients with implantable cardioverter defibrillators offer the opportunity to evaluate HRV patterns before ventricular tachycardia (VT) and under control conditions. We therefore analyzed time- and frequency-domain parameters of short-term HRV and power-law behavior of RR interval time series at rest, at 15 to 30 minutes, and immediately before VT. In comparison to control conditions, lower values of mean cycle length duration and total power were observed before VT. Spectral analysis indicated that the low- to high-frequency ratio was significantly higher (5.5 ± 0.6 vs 2.8 ± 0.3) immediately before VT than during rest. Both findings were consistent with the shift of sympathovagal balance toward sympathetic predominance and reduced vagal tone. Before VT, a more negative value of the scaling exponent β of the power-frequency relation (-1.57 ± 0.04 vs -1.33 ± 0.04) also confirmed the presence of an altered HRV pattern in comparison to controls. Thus, both abnormal autonomic modulation and dynamic patterns of HRV seem to characterize the minutes before arrhythmia onset in these patients. Copyright (C) 2000 Excerpta Medica Inc.
AB - Time- and frequency-domain analysis of heart rate variability (HRV) has been proven effective in describing alteration of autonomic control mechanisms and in identifying patients with increased cardiac and arrhythmic mortality. Patients with implantable cardioverter defibrillators offer the opportunity to evaluate HRV patterns before ventricular tachycardia (VT) and under control conditions. We therefore analyzed time- and frequency-domain parameters of short-term HRV and power-law behavior of RR interval time series at rest, at 15 to 30 minutes, and immediately before VT. In comparison to control conditions, lower values of mean cycle length duration and total power were observed before VT. Spectral analysis indicated that the low- to high-frequency ratio was significantly higher (5.5 ± 0.6 vs 2.8 ± 0.3) immediately before VT than during rest. Both findings were consistent with the shift of sympathovagal balance toward sympathetic predominance and reduced vagal tone. Before VT, a more negative value of the scaling exponent β of the power-frequency relation (-1.57 ± 0.04 vs -1.33 ± 0.04) also confirmed the presence of an altered HRV pattern in comparison to controls. Thus, both abnormal autonomic modulation and dynamic patterns of HRV seem to characterize the minutes before arrhythmia onset in these patients. Copyright (C) 2000 Excerpta Medica Inc.
UR - http://www.scopus.com/inward/record.url?scp=0034332875&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034332875&partnerID=8YFLogxK
U2 - 10.1016/S0002-9149(00)01130-9
DO - 10.1016/S0002-9149(00)01130-9
M3 - Article
C2 - 11053707
AN - SCOPUS:0034332875
VL - 86
SP - 959
EP - 963
JO - American Journal of Cardiology
JF - American Journal of Cardiology
SN - 0002-9149
IS - 9
ER -