Cardiologist-Administered Midazolam vs. Anaesthesiologist-Assisted Propofol Sedation For Transoesophageal Echocardiography-Guided Cardioversion of Atrial Fibrillation

Irregular heart rhythms, known as atrial fibrillation or atrial flutter, are common conditions that can increase the risk of stroke and heart failure. A standard treatment to restore a normal rhythm is a controlled electric shock, known as cardioversion. However, if the irregular rhythm has lasted more than 24 hours, if the duration is uncertain, and if the patient has not been on blood-thinning medication for at least three weeks, doctors must first check for blood clots in the heart. This is done using a special ultrasound scan of the heart through the food pipe. Both the scan and the electric shock treatment require sedation to make the patient relaxed or asleep. The scan uses mild sedation from a cardiologist, while the shock needs a stronger sedative given by an anaesthesiologist. But needing this extra doctor can cause delays, so patients often wait longer for treatment and to go home. This study will test whether a cardiologist can safely handle both steps using a sedative called midazolam. This study will include 220 adults at multiple hospitals in Denmark and compare this new approach to standard care. Researchers will track how quickly patients go home, how well the treatment works, any serious side effects, what patients think about the experience, and how much money can be saved. If proven safe and effective, this new method could reduce treatment delays, shorten hospital stays, and lower healthcare costs-ultimately improving care for patients and making the healthcare system more efficient.

Inclusion Criteria: * Adult patients (≥18 years) with atrial fibrillation or flutter * Scheduled for transoesophageal echocardiography-guided direct current cardioversion Exclusion Criteria: 1. Previous enrolment in the trial 2. Expected prolonged hospitalisation (\>8 hours) despite sinus rhythm restoration: * Ongoing medical needs after cardioversion (e.g., decompensation or infection) * Planned procedures after cardioversion (same-day TTE or pacemaker test allowed) * Social barriers for same-day discharge 3. Indication for anaesthesiology assistance: * Haemodynamic instability (systolic blood pressure \20 mg Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; TOE, transoesophageal echocardiography; TTE, transthoracic echocardiography.