This prospective study was initiated by the Ambulance Service Oost, Hengelo, in collaboration with the Cardiology Department of Ziekenhuis Groep Twente Hospital, Almelo, all located in the Netherlands (NL). The study was approved by the Institutional Review Board of the Maastricht University Medical Centre, as well as the Dutch Healthcare Inspection, and was registered at ToetsingOnLine, NL42344.068.12.

The on-site mobile cardioversion team consisted of an ECP (ambulance ECPs are nurse practitioners with a background in intensive care, coronary care, or emergency departments, and have years of experience in ambulance care), a sedation nurse and an ambulance driver. The ECPs belonged to a specialised group of 2 officers and all ambulance drivers within Ambulance Service Oost. The group of sedation nurses consisted of 3 officers and were made available by the Ziekenhuis Groep Twente Hospital. The ECP was 24/7 available for calls from patients reporting recurrences. In case of a reported recurrence, home cardioversion was planned taking into account the overall service schedule, with the aim of performing cardioversion as soon as possible. Because eligible patients were symptomatic, cardioversion was preferably scheduled on the same day.

Between December 12, 2018 and January 15, 2020, 100 patients in sinus rhythm after a previous successful in-hospital, propofol-supported ECV for symptomatic persistent AF were screened for participation (Fig. 1). Potential study participants were eligible for inclusion if a repeat ECV for a recurrence was deemed indicated by the attending cardiologist. Other inclusion criteria were: age between 20 and 75 years, BMI < 35 kg/m2 and demonstrated adherence to oral anticoagulation. Patients were required to have an American Society of Anaesthesiologists (ASA) score below 3 [10]. Patients with significant structural heart disease, known sick sinus syndrome or other arrhythmias, or those with a pacemaker or implantable cardioverter-defibrillator were excluded. Additionalexclusion criteria included severe comorbidities such as kidney dysfunction (eGFR ≤ 30 ml/min), pulmonary dysfunction (FEV1 < 1 litre), and active malignancy.

Infographic. The figure shows the study procedures, flow of patients, distribution of tasks among attending care officers, and patients’ outcomes. AF atrial fibrillation, ECP emergency care practitioner, ECV electrical cardioversion, SR sinus rhythm

Out of 27 eligible patients, 25 provided informed consent (Fig. 1). To ensure safe cardioversion, the ambulance service’s ECP examined the patients’ homes for accessibility, hygiene, adequate space and lighting, electrical interference and explosive sources (e.g., oxygen tanks), electricity network stability, and the presence of an adequate informal caregiver overnight, usually a relative. Consenting patients were instructed to call the ECP if they experienced a recurrence of AF. At the time of recurrence—and well before the actual cardioversion—potential intercurrent conditions such as heart failure or acute coronary syndrome were excluded. In addition, the indication for the repeat cardioversion was reconfirmed by the attending cardiologist.’

Of the 25 consenting patients, six developed one or two recurrences of AF and underwent ECV at their homes (Tab. 1). Patients were instructed to fast at least 6 h before the scheduled cardioversion time. To ensure optimal use of resources, the procedures were planned in downtime windows with peak availability of ambulance, ECV team members and remote supervision by a cardiologist. One hour before the intervention, the ECP arrived at the patient’s home to confirm AF using a portable Corpuls‑3 device (Corpuls® BV, Hellevoetsluis, NL), and to perform point-of-care tests to check potassium and INR level (if vitamin K antagonists were used). If all checks were in order, the cardiologist’s approval was acquired by telephone consultation.

Thereafter, the ambulance driver and sedation nurse would arrive at the patient’s home. Although the ambulance team could manage most complications on-site using current national ambulance sector protocols, the ambulance’s presence was required to ensure hospital transfer if necessary. Patients were positioned on the ambulance stretcher—mostly in the patient’s living room—and connected to the Corpuls‑3 monitor; propofol sedation was then started. The stretcher is the natural treatment environment of the ECP, facilitated interventions in case of complications and was also used for ergonomic reasons (e.g. adjustable height and (anti‑)Trendelenburg position). ECV was performed using synchronised biphasic 200 Joules shocks. After successful cardioversion, return of consciousness (Aldrete score ≥ 9) [11] and stable vital signs were confirmed. The ambulance driver and sedation nurse then leave the scene. After one additional hour of stable consciousness, normal pulse, blood pressure, respiration, oxygen saturation, and carbon dioxide concentration, the ECP handed over care to the informal caregiver and debrief the supervising cardiologist. Follow-ups were performed by the ECP at 6 and 24 h, assessing AF recurrence (by symptoms and, an if indicated, ECG), complications (via questionnaire), and patient satisfaction (by asking preference for either procedure). An outpatient cardiologist visit followedat 6 weeks to evaluate the rhythm status and any complications. The complete protocol is presented in the Supplement. All data, including ECV outcomes, were recorded in the patient’s electronic medical record. Descriptive statistics were used to summarise patients’ characteristics and outcomes.