Effects of propofol sedation on pacing thresholds : Results from an observational cohort study

Propofol is one of the most commonly used intravenous anaesthetic drugs for surgical procedures. The use of propofol for sedation is also common practice during endoscopic procedures, electrophysiology studies, and ablation procedures, as well as pacemaker and defibrillator implantation. It was found that propofol alters the electrophysiologic properties of the heart and its conduction system. The effects of propofol on pacing thresholds are unknown and could have implications for pacemaker (PM) and defibrillator (ICD) implantation procedures, as well as sedation and anaesthesia in PM and ICD patients in general.

We sought to investigate the effects of propofol sedation on atrial and right ventricular pacing thresholds in PM and ICD patients.

A total of 50 patients with PM, ICD, or cardiac resynchronization therapy (CRT) undergoing propofol sedation for electrophysiology (EP) investigation, transesophageal echocardiography (TEE), electrocardioversion (ECV), or bronchoscopy were included prospectively. Pacing thresholds, impedance, and sensing were assessed by device interrogation immediately prior to sedation and after the desired sedation depth was achieved by the administration of propofol.

Mean atrial (0.68 V vs 0.77 V, p = 0.136) and mean right ventricular thresholds (0.90 V vs 0.93 V, p = 0.274) remained unchanged. Impedances and sensing remained unaffected in all patients.

Propofol sedation did not affect pacing thresholds of atrial and right ventricular leads in this cohort of PM and ICD patients.