Atrial Fibrillation, Deep Sedation, Electric Countershock
Conditions
Keywords
atrial fibrillation, Electric Countershock, sedation, bispectral index, propofol, anesthesia recovery
Brief summary
Electrical cardioversion (ECV) is a standard procedure used to restore normal heart rhythm in patients with atrial fibrillation (AF) by delivering a brief electrical shock to the heart. Because the procedure is painful and distressing, patients receive sedation - a controlled state of reduced consciousness - using short-acting intravenous medications. However, the optimal depth of sedation for ECV has not been well defined: too deep may cause breathing problems and low blood pressure, while too light may result in pain, awareness, or patient movement during the shock. Bispectral index (BIS) monitoring is a non-invasive technology that continuously measures brain activity using an EEG sensor placed on the forehead, generating a numerical score from 0 (no brain activity) to 100 (fully awake). BIS scores between 61 and 80 correspond to moderate sedation, which preliminary observations suggest may be sufficient for ECV without the risks associated with deeper sedation. This randomized controlled trial will compare two approaches to sedation monitoring during elective ECV for AF: * Group 1 (BIS Group): Sedation is guided by BIS monitoring, targeting a score of 61-80. * Group 2 (Control Group): Sedation is guided by standard clinical assessment (loss of response to verbal commands and eyelash reflex), with BIS recorded but not visible to the treating team. Both groups will receive the same medications (propofol and fentanyl). The primary outcome is how quickly patients recover after the procedure, measured by the Modified Aldrete Score - a standard clinical recovery assessment tool. Secondary outcomes include patient and physician satisfaction, procedural pain, risk of awareness during the procedure, cardioversion success rate, hemodynamic stability, and complication rates. The trial will enroll 60 adult patients at Istanbul University-Cerrahpasa Cardiology Institute. Findings are expected to provide evidence-based guidance for standardizing sedation protocols during ECV.
Detailed description
Background: Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia. Elective electrical cardioversion (ECV) is a widely used rhythm control strategy. Procedural sedation is a critical component of ECV; however, the optimal monitoring method and depth of sedation remain undefined. Excessive sedation risks respiratory depression and hemodynamic instability, particularly in patients with structural heart disease, while inadequate sedation may result in patient movement, pain, and procedural awareness. Bispectral index (BIS) monitoring offers objective, real-time quantification of sedation depth. Preliminary clinical observation at our center suggests that BIS 61-80 provides adequate procedural conditions for ECV with propofol-fentanyl sedation, while deeper sedation (BIS \<60) is associated with increased respiratory depression without additional procedural benefit.
Interventions
DRUGBIS-guided propofol sedation
IV propofol 0.5-1 mg/kg titrated to BIS 61-80, preceded by IV fentanyl 0.5-1 µg/kg. Additional propofol 0.25-0.5 mg/kg boluses as needed for repeat shocks within target range.
DRUGClinical-guided propofol sedation
IV propofol 0.5-1 mg/kg titrated to clinical endpoints, preceded by IV fentanyl 0.5-1 µg/kg. BIS recording passive (blinded to operator).
Sponsors
Istanbul University - Cerrahpasa
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥18 years * Documented atrial fibrillation with indication for elective electrical cardioversion * American Society of Anesthesiologists (ASA) physical status class I, II, or III * Left ventricular ejection fraction ≥30% on echocardiography * Adequate anticoagulation: INR ≥2.0, OR ≥3 weeks of therapeutic anticoagulation, OR absence of left atrial thrombus confirmed by transesophageal echocardiography * Ability and willingness to provide written informed consent
Exclusion criteria
* Known allergy or contraindication to propofol or fentanyl, or their excipients (soy, egg) * Hemodynamic instability (systolic blood pressure \<90 mmHg or symptomatic hypotension) * Decompensated heart failure (NYHA functional class IV) * Severe obstructive sleep apnea requiring CPAP or BiPAP therapy * Anticipated difficult airway (modified Mallampati classification class III or IV) * Baseline oxygen saturation \<94% or active chronic obstructive pulmonary disease * Severe hepatic impairment (transaminases \>3× upper limit of normal) or severe renal impairment (eGFR \<30 mL/min/1.73m²) * Active psychiatric illness or cognitive impairment precluding questionnaire completion * Pregnancy or breastfeeding * Alcohol or substance use within the preceding 24 hours * Prior participation in this trial
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to Recovery (Modified Aldrete Score ≥9) | From sedation induction to Modified Aldrete Score ≥9, assessed every 5 minutes post-ECV for up to 60 minutes. | Time in minutes from sedation induction (first propofol dose) to achievement of Modified Aldrete Score ≥9, assessed by an independent, blinded anesthesiologist. The Modified Aldrete Score evaluates activity, respiration, circulation, consciousness, and oxygen saturation (0-2 points each; maximum 10). Score ≥9 indicates readiness for discharge from monitored care. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Patient Satisfaction | Within 60 minutes post-procedure. | Patient-reported global satisfaction with the procedure assessed using a 5-point Likert scale (1 = very dissatisfied to 5 = very satisfied), administered by the blinded assessor after Modified Aldrete Score ≥9 is achieved. |
| Physician Satisfaction | Immediately post-procedure (within 5 minutes of ECV completion). | Treating cardiologist's global satisfaction with sedation conditions assessed using a 5-point Likert scale (1 = very dissatisfied to 5 = very satisfied), recorded immediately after the procedure. |
| Procedural Pain | Within 60 minutes post-procedure (after Modified Aldrete Score ≥9). | Patient-reported pain intensity during the procedure assessed using the Numeric Rating Scale-11 (NRS-11; 0 = no pain, 10 = worst imaginable pain), administered after recovery. |
| Cardioversion Success Rate | Within 1 hour post-ECV. | Proportion of patients achieving restoration of sinus rhythm confirmed by 12-lead ECG within 1 hour of the procedure. |
| Incidence of sedation related complications | From sedation induction to 60 minutes post-procedure. | Proportion of patients experiencing any of the following: hypotension (systolic BP \<90 mmHg), bradycardia (HR \<50 bpm), oxygen desaturation (SpO₂ \<90%), apnea, laryngospasm, or procedurally significant arrhythmia. Recorded as a composite binary outcome (yes/no). |
| Total Anesthetic Drug Consumption | During procedure | Total dose (mg/kg) of propofol and fentanyl (µg/kg) administered during the procedure. |
| Number of Cardioversion Shocks and Total Energy Delivered | During the ECV procedure. | Total number of synchronized shocks delivered and cumulative energy (Joules) used per patient. |
Countries
Turkey (Türkiye)
Contacts
CONTACTAYLA ESIN
PRINCIPAL_INVESTIGATORKerem Erkalp, Professor Dr
Istanbul University - Cerrahpasa
Outcome results
None listed