Torsades de Pointes, the twisting ribbon!
Review of Long QT syndrome, predisposing factors, mechanism, Treatment and prevention in the perioperative period
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J Anesth. 2013 Feb 15. [Epub ahead of print]
QT interval abnormalities: risk factors and perioperative management in long QT syndromes and Torsades de Pointes.
Kaye AD, Volpi-Abadie J, Bensler JM, Kaye AM, Diaz JH.
Source Department of Anesthesiology, LSU School of Medicine, Room 656, 1542 Tulane Ave., New Orleans, LA, 70112, USA, alankaye44@hotmail.com.
PMID: 23412014
====== Letters from listeners ======
Dr. Saied,
Excellent job on the podcasts, I appreciate your hard work and effort.
I just had one point. I have had two electrophysiology patients, one with borderline QT interval prolongation and one with congenital QT interval prolongation. Both of them were very anxious teenagers and refused iv's until after they were asleep. Both of them had baseline ECG's while in the EP study room prior to induction with Sevoflurane/N2O and continuous ECG's monitored by the cath room tech.
1. The borderline QT interval prolongation patient developed more prolonged QT interval after Sevoflurane mask induction. The EP physician asked us if there was anything else we could use and we used Propofol TIVA after which the QT went back to baseline and we finished the study.
2. For the second patient, we explained to the patient and family the risk of prolonged QT interval and inhalational agents and that we would like to have an iv for Propofol TIVA so we could avoid inhaled agents, but the patient refused and wanted to be asleep for the iv. The patient with congenital prolonged QT interval was masked induced with Sevoflurane/N2O with an immediate plan to switch to Propofol TIVA after an iv was placed. As the iv was being placed the patient had further prolonging of the QT interval and an episode of Torsades that self resolved within seconds. In the meantime we switched off the Sevoflurane and started propofol, no issues after this. The EP physician confirmed this in real time with their ECG readings and printed me a copy.
These are two examples of what many do not know in anesthesia, and should be aware of, Halogenated inhaled agents prolong the QT interval and can lead to Torsades in patients with congenital QT prolongation.
Keep up the good work.
SA
