Abstract

Background: Atrial fibrillation (AF) is a leading cause of ischemic stroke, often underdiagnosed in acute settings. Objective: To determine the prevalence of AF in hospitalized ischemic stroke patients and analyze associated clinical characteristics. Methods: A prospective cross-sectional study was conducted on 99 patients with acute ischemic stroke admitted to Thong Nhat Hospital from January 2024 to March 2025. AF was diagnosed using a 12-lead ECG and 24-hour Holter monitoring. Clinical and paraclinical data were analyzed to compare AF vs. non-AF groups. Results: AF was present in 15.2% of patients. The AF group was significantly older (81.7 vs. 64.8 years, p < 0.001), had higher stroke severity (NIHSS 12.9 vs. 6.2, p < 0.001), and more frequent impaired consciousness. Comorbidities, including hypertension, diabetes, and heart failure, were more prevalent. Echocardiography revealed larger left atrial diameters and reduced ejection fraction. Neuroimaging showed a higher rate of large infarcts (> 30 mm), lower ASPECT scores, and more extensive brain damage. Biochemical abnormalities included higher glucose, triglycerides, LDL-c, and cholesterol, and lower HDL-c and eGFR levels in AF patients. Conclusion: The study confirms the high prevalence of AF in ischemic stroke patients, especially in older individuals with cardiovascular comorbidities. Early rhythm monitoring is critical for diagnosis and secondary prevention.