Postoperative atrial fibrillation (POAF) occurs in approximately 20% of patients following thoracic surgery. Early diagnosis is essential to prevent complications such as heart failure, stroke, myocardial infarction, and increased mortality. Smartwatches equipped with single-lead ECG capabilities and algorithms to detect asymptomatic atrial fibrillation (AF) offer a potential solution. This study aims to evaluate the effectiveness of smartwatches in detecting POAF compared to standard care.

Inclusion Criteria:

• Adults (>18 years old).
• Patients undergoing major thoracic surgery with one-lung ventilation within the past 48 hours.
• Scheduled pneumonectomy or lobectomy.
• Admission to a conventional surgical unit postoperatively.
• Ability to perform single-lead ECG using a smartwatch.
• Coverage under a social security system.
• Signed informed consent

Exclusion Criteria:

• History of atrial fibrillation.
• Requirement for telemetry for AV block or tachyarrhythmias (>140 bpm).
• Dependency on a pacemaker.
• Participation in another interventional clinical trial affecting POAF incidence.
• Mediastinal, pleural, or chest wall surgery.
• Reoperations or surgeries performed more than 48 hours prior.
• Pregnant women.
• Patients under guardians or similar legal protection.