The effects of volatile anesthetics on the Q-Tc interval.
OBJECTIVE
To examine the effects of halothane, isoflurane, and sevoflurane on Q-Tc interval (corrected for heart rate) during inhalation induction of anesthesia.


METHODS
Prospective, double-blind, randomized study.


METHODS
Departments of Cardiology and Anesthesiology in a university hospital.


METHODS
Patients undergoing noncardiac surgery.


METHODS
A total of 65 American Society of Anesthesiologists physical status I-II patients, aged 16 to 50 years, undergoing general anesthesia, were randomly allocated to receive halothane, isoflurane, or sevoflurane.


RESULTS
The time to reach the predetermined end-tidal concentrations of 3 minimum alveolar concentration was 6 to 10 minutes. When compared with preinduction values, heart rate decreased after halothane (p < 0.01) and sevoflurane (p < 0.05) administration; in contrast, heart rate increased after induction of anesthesia with isoflurane (p < 0.05). The mean QRS intervals were not significantly changed after halothane, isoflurane, or sevoflurane. The Q-Tc interval was increased with isoflurane compared with baseline (465 +/- 23 v 441 +/- 18 msec, p < 0.01), not changed with sevoflurane (441 +/- 17 v 434 +/- 19 ms, p > 0.05), and shortened with halothane (426 +/- 23 v 445 +/- 21 msec, p < 0.01).


CONCLUSIONS
Sevoflurane or halothane may be preferred to isoflurane in patients with conditions that are known to induce a prolonged Q-Tc interval. The effects of Q-Tc interval changes resulting from different anesthetic agents on morbidity and the incidence of arrhythmias during anesthesia warrant further investigation.
Güler
N
N
Department of Cardiology, School of Medicine Yüzüncü Yil University, Van, Turkey. niyaziguler@hotmail.com
Kati
I
I
Demirel
C B
CB
Bilge
M
M
Eryonucu
B
B
Topal
C
C
D000293:Adolescent; D000328:Adult; D000769:Anesthesia, Inhalation / Q000009:adverse effects*; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006221:Halothane / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007530:Isoflurane / Q000009:adverse effects*; D008297:Male; D008738:Methyl Ethers / Q000009:adverse effects*; D008875:Middle Aged; D011446:Prospective Studies; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D007530:Isoflurane; D006221:Halothane