Propofol suppresses the His‐ventricular conduction in paediatric patients

Abstract

What is known and objective Propofol is the most commonly used intravenous anaesthetic worldwide and is considered to be safe for all ages. However, there have been some reports that propofol induces severe atrioventricular (AV) blocks in humans and some studies demonstrated that propofol suppressed the cardiac conduction system in animals. A precise mechanism by which the block is induced has not been elucidated yet in humans. The objective of this study was to investigate the effects of propofol on the cardiac conduction system and the cardiac autonomic nervous balance in children. Methods We enrolled 23 paediatric patients (age: 6‐15 years; males: 16, females: 7) who were scheduled to undergo radiofrequency catheter ablation (RFCA) under general anaesthesia. Anaesthesia was induced with 2 mg/kg propofol and 0.5 µg/kg/min remifentanil, and tracheal intubation was performed with the aid of 1 mg/kg rocuronium. Anaesthesia was maintained with 5‐7 mg/kg/h propofol and 0.2 µg/kg/min remifentanil during the RFCA. After the completion of the RFCA, anaesthesia was further maintained with 5 mg/kg/h propofol and 0.2 µg/kg/min remifentanil for at least 10 min (LC: low propofol concentration state), followed by the injection of 2 mg/kg propofol and the infusion of 10 mg/kg/h propofol for 10 min (HC: high propofol concentration state). The sinus node recovery time (SNRT), sinoatrial conduction time (SACT), atrial‐His (AH) interval and the His‐ventricular (HV) interval were measured at the end of both the LC and HC. Cardiac autonomic regulation was simultaneously assessed based on heart rate variability. Results and discussion Propofol significantly suppressed intrinsic cardiac HV conduction, but did not affect the SNRT, SACT or the AH interval. As HV blocks, which occur below the His bundle, are often life‐threatening, the HV conduction delay may be a cause of severe AV blocks induced by propofol. Propofol directly suppressed parasympathetic nerve activity, and sympathetic nerve activity was also suppressed. What is new and conclusion These results indicate that propofol suppresses the HV conduction and might help to elucidate the mechanism by which propofol causes lethal AV blocks.

The Chronotropic Function of Propofol and the Underlying Mechanism in Rabbits

“…Compared with the baseline at T0, there was no difference in the discharge of the vagus nerve at 10 min after intravenous administration, which was considered to be related to propofol pharmacokinetic characteristics. Previous studies showed that the heart rate decrease induced by propofol could not be fully explained by the central vagus effect, that is, it may also have a direct inhibitory effect on the sinoatrial node [5]. In this study, we observed the effect of propofol on the action potential of pacemaker cells in the isolated rabbit sinoatrial node.…”

“…It is generally agreed that bradycardia is regulated by the propofol antisympathetic effect. However, some studies showed that the decrease of heart rate induced by propofol could not be completely explained by the effect of the central vagus nerve, that is, propofol may also have a direct inhibitory effect on the sinoatrial (SA) node [5,6].…”

Remimazolam as the Primary Agent for Sedation During Cardiac Catheterization in Three Patients With Comorbid Cardiac Conduction Abnormalities

“…These have been noted in patients with and without pre-existing conduction defects. Further information into the specific effects of propofol on cardiac electrophysiologic function have been provided by Matsushima et al in their prospective study of 23 pediatric patients undergoing radiofrequency catheter ablation during general anesthesia with propofol [ 16 ]. The sinus node recovery time (SNRT), sinoatrial conduction time (SACT), atrial-His (AH) interval, and the His-ventricular (HV) interval were measured.…”

Comparative Analysis of the Hemodynamic Effects of Remimazolam and Propofol During General Anesthesia: A Retrospective Study

“…In contrast, propofol is known to (1) suppress the parasympathetic nervous system more strongly than the sympathetic nervous system [ 12 , 13 ] and (2) inhibit the cardiac vagus nerve in the nucleus, which is associated with the parasympathetic nervous system [ 31 ].…”