Effects of conscious sedation on tachycardia inducibility and patient comfort during ablation of supraventricular tachycardia: a double blind randomized controlled study.

Aims: Sedation is not consistently used during electrophysiology procedures because of concerns regarding effects on tachycardia inducibility. We designed this study to assess the effect of conscious sedation on tachycardia inducibility and patient comfort during supraventricular tachycardia ablation.

Methods and results: Patients with narrow QRS tachycardia and no pre-excitation undergoing an electrophysiology study were randomly assigned to sedation or placebo group. Patients in the sedation group received intermittent doses of midazolam and fentanyl, while those in the placebo group received normal saline as placebo. The physician and the patient were blinded to the allocation. Information was collected on tachycardia inducibility, patient discomfort, and complications. A total of 103 patients were included in the study. Proportion of patients with difficult tachycardia induction (27.4% vs. 32.7%) or with non-inducibility (5.8% vs. 3.8%) were not different between the sedation and placebo groups. Patient discomfort as measured by the Wong-Baker scale was significantly less in the sedation group (1.45 ± 1.08 vs. 2.24 ± 1.2, P < 0.0007) compared to the placebo group. There was no difference in incidence of hypotension or hypoxia between the two groups.

Conclusions: Conscious sedation with intermittent midazolam- and fentanyl-reduced patient discomfort during electrophysiology study and ablation of supraventricular tachycardia without affecting tachycardia inducibility. Sedation administered in the absence of an anaesthetist was safe.