Atrial fibrillation post hematopoietic stem cell transplant: incidence, risk factors, and management challenges.

Atrial fibrillation (AF) is the most frequent cardiovascular complication after hematopoietic stem cell transplantation (HSCT) and is linked to higher short-term and long-term morbidity and mortality. AF occurring within 30 days post-HSCT reflects an interplay of peri-transplant triggers, conditioning-related myocardial injury, systemic inflammation and infection, rapid fluid shifts with atrial stretch, and electrolyte disturbances. Beyond 30 days, AF is driven by chronic inflammation and graft-vs.-host disease, metabolic dysregulation from immunosuppression, and cumulative cardiotoxic cancer therapies. Management is challenged by thrombocytopenia and drug-drug interactions. In the acute phase, meticulous volume and electrolyte optimization is essential. When AF duration is ≤48 h, preferably ≤12 h, rhythm control (often with amiodarone) may be pursued; otherwise, rate control is generally favored, with beta-blockers preferred. Long-term care should individualize rate vs. rhythm strategies and reassess anticoagulation as counts recover, given potential thromboembolic risk. Prospective studies and HSCT-specific AF risk tools are needed to guide prevention and treatment.