2026 FSA Podium and Poster Abstracts

Introduction: Rubinstein–Taybi syndrome (RTS) is a rare genetic disorder typically caused by mutations in the CREBBP gene and characterized by craniofacial and skeletal abnormalities, developmental delay, and congenital heart defects (1). While structural heart anomalies like atrial and ventricular septal defects are well documented in the literature, little is known about associated conduction abnormalities. Few cases of perioperative supraventricular tachycardia and multifocal premature atrial/ventricular contractions have been reported after administration of succinylcholine, atropine and neostigmine (1,2) but we found no published cases of associated QTc prolongation. Volatile anesthetics, particularly Sevoflurane, are known to prolong the QT interval via inhibition of rapid potassium rectifier channels which prolongs action potential duration (3). While risk of QTc prolongation is higher in patients with congenital long QT syndrome or those taking QT prolonging drugs, the association with RTS is unclear. We report a case of significant QTc prolongation associated with Sevoflurane exposure in a child with RTS.

Methods: A 2 year old male with RTS secondary to a heterozygous pathogenic CREBBP variant presented for right orchiopexy. He was born at 37 weeks without perinatal complications. Medical history was notable for global developmental delay, atrial septal defect (cleared by cardiology preoperatively), gastrostomy tube placement, and inguinal hernia repair. The patient was not on any home medications. During a prior MRI under general anesthesia, QTc prolongation >500 ms was observed while receiving Sevoflurane, which improved after transition to total intravenous anesthesia (TIVA). Preoperative EKG demonstrated QTc values ranging from 320–450 ms. Preoperative lab work was unremarkable. 

Results: In the operating room, QTc immediately prior to induction was 483 ms. Inhalational induction was performed with 5% Sevoflurane. Following intubation, Sevoflurane was titrated to achieve a minimum alveolar concentration (MAC) < 0.3 and general anesthesia was maintained with a Propofol infusion at 150 mcg/kg/min and small boluses of Dexmetodimidine. Within 15 minutes of induction, QTc peaked at 608 ms after which it gradually decreased, ranging between 514-541 ms. After the volatile anesthetic was discontinued and upon emergence and extubation, the QTc returned close to baseline at 503 ms (Figure 1). No malignant arrhythmias were observed.

Discussion/Conclusion: This case demonstrates reproducible QTc prolongation temporally associated with Sevoflurane exposure in a child with RTS. Although volatile anesthetics are known to prolong QTc, this degree of prolongation (>600 ms) raises concern for increased susceptibility in patients with RTS. Improvement with initiation of TIVA and reduction of Sevoflurane concentration suggests a dose-dependent effect. Given the potential risk for malignant arrhythmias such as torsades de pointes when QTc is above 500–550 ms, avoidance or minimization of volatile agents and continuous intraoperative QT monitoring should be considered. For these patients, TIVA can be used as a safe alternative due to Propofol’s minimal effect on the QT interval.

References:

1. Rath A, et a. Anaesthetic and Perioperative Implications of Rubinstein-Taybi Syndrome. Airway. 2021; 4(3):p 191-195. 

2. Stirt JA. Succinylcholine in Rubinstein-Taybi Syndrome. The Journal of the American Society of Anesthesiologists. 1982; 57(5):p 429.