Ventricular tachycardia during general anesthesia in a patient with congenital long QT syndrome

Abstract

P Pu ur rp po os se e: : Congenital long QT syndrome is characterized by a corrected QT interval of at least 440 msec on the electrocardiogram and has been associated with recurrent syncope, documented ventricular arrhythmia and sudden death. There have been numerous articles over the past 20 years describing isolated instances of surgical and anesthesia related complications but the general anesthetic management of the condition remains unclear.C Cl li in ni ic ca al l f fe ea at tu ur re es s: : An 11-yr-old female with documented long QT syndrome, with two episodes of syncope in the past, was admitted for emergency drainage of left periorbital cellulitis. Anesthesia was induced with propofol, fentanyl and rocuronium, and initially maintained with nitrous oxide and halothane. After 20 min, the patient developed ventricular tachycardia (torsade de pointes). Lidocaine 1 mg·kg -1 iv was given and the rhythm reverted to normal sinus. Halothane was discontinued and the surgery proceeded without further incident.C Co on nc cl lu us si io on ns s: : Our review of the literature revealed that patients with long QT syndrome whose symptoms are well controlled prior to surgery tend to do well regardless of the anesthetic chosen. There are, however, theoretical reasons to avoid anesthetics which either sensitize the myocardium to catecholamines or which cause an increase in circulating levels of catecholamines.

Pharmacogenomics of anesthetic drugs in transgenic LQT1 and LQT2 rabbits reveal genotype-specific differential effects on cardiac repolarization

“…Nevertheless, the death of two LQT2 rabbits from TdP induced by propofol anesthesia calls this recommendation into question, especially in the case of LQT2 mutations. Several case reports demonstrate the risk of anesthesia-induced malignant pVT in human LQT patients, particularly during anesthesia with I Ks -blocking agents like halothane (2), sevoflurane (40), or propofol (18,34). However, no data are available on the underlying genotype of these patients.…”

“…3 and 15). The risk for anesthesiainduced malignant pVT is particularly pronounced in individuals with congenital long QT (LQT) syndromes (LQTS) (2,14,17,18,31,35,40) (12) are responsible for the LQT1 and LQT2 phenotypes, respectively. Furthermore, subtle mutations in LQT-related genes can predispose healthy individuals to drug-induced QT prolongation and ventricular arrhythmia (20,22,29,51).…”

“…3 and 15). The risk for anesthesiainduced malignant pVT is particularly pronounced in individuals with congenital long QT (LQT) syndromes (LQTS) (2,14,17,18,31,35,40), a genetically heterogeneous disease characterized by impaired cardiac repolarization leading to QT prolongation, spontaneous torsade de pointes (TdP), and sudden cardiac death (SCD) (reviewed in Ref. 32).…”

Anaesthetics and the rate corrected interval: learning from droperidol?

“…It therefore remains difficult to advise on the safest anaesthetic agents to use [8]. However, patients with LQTS whose symptoms are well controlled before surgery tend to do well regardless of the anaesthetic chosen [19]. Of the intravenous induction agents, limited clinical evidence suggests that propofol is the most suitable agent to use for induction and maintenance [8,17].…”

“…There are theoretical reasons to avoid anaesthetics that either sensitize the myocardium to catecholamines or cause an increase in circulating levels of catecholamines [19].…”