TY - JOUR
T1 - Sympathetic nerve activity in the congenital long-QT syndrome
AU - Shamsuzzaman, Abu S.M.
AU - Ackerman, Michael J.
AU - Kara, Tomas
AU - Lanfranchi, Paola
AU - Somers, Virend K.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/4/15
Y1 - 2003/4/15
N2 - Background - Patients with congenital long-QT syndrome (LQTS) are susceptible to life-threatening arrhythmias. The sympathetic nervous system may have an important triggering role for cardiovascular events in LQTS. We therefore examined measurements of sympathetic neural traffic in patients with LQTS and matched control subjects. Methods and Results - Twelve patients with congenital LQTS and 12 healthy volunteers matched for age, sex, and body mass index were studied. Heart rate, respiration, blood pressure, and sympathetic nerve activity to the skeletal muscle blood vessels (muscle sympathetic nerve activity) and to the skin (skin sympathetic nerve activity) were monitored and recorded continuously. Resting heart rate (P = 0.03), muscle sympathetic nerve activity burst rate (P=0.008), and burst incidence (P = 0.02) were lower in patients with LQTS than in control subjects. However, skin sympathetic nerve activity was very similar in patients with LQTS and control subjects. Spectral analysis of RR variability showed a decreased low-frequency component, an increased high-frequency component, and a decrease in the ratio of the low-frequency component to the high-frequency component in patients with LQTS (P = 0.01). Conclusions - LQTS is associated with a selective reduction in sympathetic drive to muscle blood vessels and perhaps also to the heart.
AB - Background - Patients with congenital long-QT syndrome (LQTS) are susceptible to life-threatening arrhythmias. The sympathetic nervous system may have an important triggering role for cardiovascular events in LQTS. We therefore examined measurements of sympathetic neural traffic in patients with LQTS and matched control subjects. Methods and Results - Twelve patients with congenital LQTS and 12 healthy volunteers matched for age, sex, and body mass index were studied. Heart rate, respiration, blood pressure, and sympathetic nerve activity to the skeletal muscle blood vessels (muscle sympathetic nerve activity) and to the skin (skin sympathetic nerve activity) were monitored and recorded continuously. Resting heart rate (P = 0.03), muscle sympathetic nerve activity burst rate (P=0.008), and burst incidence (P = 0.02) were lower in patients with LQTS than in control subjects. However, skin sympathetic nerve activity was very similar in patients with LQTS and control subjects. Spectral analysis of RR variability showed a decreased low-frequency component, an increased high-frequency component, and a decrease in the ratio of the low-frequency component to the high-frequency component in patients with LQTS (P = 0.01). Conclusions - LQTS is associated with a selective reduction in sympathetic drive to muscle blood vessels and perhaps also to the heart.
KW - Apnea
KW - Heart rate
KW - Long-QT syndrome
KW - Nervous system, sympathetic
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U2 - 10.1161/01.CIR.0000066284.34258.59
DO - 10.1161/01.CIR.0000066284.34258.59
M3 - Article
C2 - 12682002
AN - SCOPUS:0344088467
SN - 0009-7322
VL - 107
SP - 1844
EP - 1847
JO - Circulation
JF - Circulation
IS - 14
ER -