ATRIAL FIBRILLATION IN CRITICAL ILLNESS: A COMPREHENSIVE REVIEW OF DIAGNOSIS, HEMODYNAMIC IMPACT, AND MANAGEMENT STRATEGIES

Abstract

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia observed in critically ill patients and is linked to substantial morbidity and mortality. In the intensive care setting, AF frequently reflects systemic physiological stress and may exacerbate hemodynamic instability, predisposing patients to organ dysfunction and thromboembolic events. New-onset AF (NOAF) is of particular concern, as it often signifies worsening severity of illness in conditions such as sepsis, multi-organ failure, or major postoperative states. Objective: To review the clinical significance, epidemiology, diagnostic workup, associated complications, and evidence-based management strategies for atrial fibrillation in critically ill patients, with particular emphasis on hemodynamic stabilization, rate and rhythm control, and individualized anticoagulation. Study Design: Narrative review. Setting: Intensive care unit (ICU) and critical care populations. Duration of Study: last six years literature was searched. Methods: This narrative review synthesizes current evidence, contemporary guideline recommendations, and major studies addressing the epidemiology, pathophysiology, hemodynamic consequences, diagnostic evaluation, and therapeutic approaches for AF in the ICU. Literature from critical care, cardiology, and electrophysiology sources was examined to outline best practices and emerging perspectives. Results: Atrial fibrillation in the ICU is consistently associated with increased mortality, prolonged hospital and ICU length of stay, and a heightened risk of stroke and organ dysfunction. Diagnostic evaluation relies on electrocardiography, transthoracic echocardiography, and targeted laboratory testing to identify reversible precipitants, including sepsis, electrolyte abnormalities, and hypovolemia. Rate control is the preferred initial strategy in hemodynamically stable patients, commonly employing beta-blockers or calcium channel blockers. Rhythm control, most frequently using amiodarone, may be advantageous in patients with persistent hypotension or inadequate rate control. Anticoagulation provides substantial protection against thromboembolic events, although decisions must balance stroke risk with bleeding risk, renal function, and planned procedures. Use of standardized scores such as CHA₂DS₂-VASc and HAS-BLED supports individualized decision-making. Conclusion: Atrial fibrillation in critically ill patients serves as a marker of physiological deterioration and is an independent predictor of adverse outcomes. Optimal management requires prompt identification, correction of underlying triggers, evidence-based rate or rhythm control strategies, and carefully individualized anticoagulation. Further research is needed to develop ICU-specific AF management algorithms and to clarify the long-term prognostic implications of new-onset AF.