Effects of head-up tilt after stellate ganglion block on QT interval and QT dispersion.
OBJECTIVE
The aim of this study is to examine the effects of head-up tilt (70 degrees ) 30 minutes after right or left stellate ganglion block (SGB) on RR interval, QT interval, the rate-corrected QT (QTc) interval, QT dispersion (QTD), and the rate-corrected QT dispersion (QTcD) using computerized measurement.


METHODS
Ten healthy volunteers underwent both right and left SGBs using 7 mL 1% mepivacaine with a 7-day interval between the two blocks. A 12-lead electrocardiogram was monitored to measure parameters before SGB; 30 minutes after SGB (before head-up tilt); and immediately, 5, 10, and 15 minutes after head-up tilt.


RESULTS
Right SGB induced significant increases in QT interval, QTc interval, QTD, and QTcD from 30 minutes after the block through 15 minutes after head-up tilt. There were significant increases of QT interval, QTc interval, and QTcD between before and immediately after head-up tilt in right SGB. Left SGB induced significant decreases of QT interval and QTc interval from 30 minutes after SGB through 15 minutes after head-up tilt. Left SGB also induced a significant decrease of QTD from immediately after through 10 minutes after head-up tilt.


CONCLUSIONS
Significant increases of QT interval, QTc interval, and QTcD, which are associated with an increased risk of ventricular arrhythmias and cardiac events, occur immediately after head-up tilt in right SGB. However, head-up tilt does not induce increases of QT interval, QTc interval, QTD, and QTcD in left SGB.
Department of Anesthesiology, Dokkyo University School of Medicine, Tochigi, Japan.
Koichi
K
Fujii
Shigeki
S
Yamaguchi
Hirotoshi
H
Egawa
Shinsuke
S
Hamaguchi
Toshimitsu
T
Kitajima
Junichi
J
Minami
D000328:Adult; D000779:Anesthetics, Local / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography / Q000379:methods*; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008619:Mepivacaine / Q000627:therapeutic use; D009407:Nerve Block / Q000379:methods*; D011187:Posture / Q000502:physiology*; D012016:Reference Values; D013233:Stellate Ganglion / Q000187:drug effects*; D016683:Supine Position / Q000502:physiology; D018667:Tilt-Table Test / Q000379:methods; D013997:Time Factors
D000779:Anesthetics, Local; D008619:Mepivacaine