Right-side propensity of cardiogenic emboli in acute ischemic stroke with atrial fibrillation

OBJECTIVES: We attempted to determine the propensity for sidedness of cardiogenic emboli associated with atrial fibrillation (AF) by comparing the sides on which microembolic signals (MES) were detected via transcranial Doppler (TCD) monitoring and the location of infarcts on magnetic resonance imaging. DESIGN: Patients with AF on Holter monitoring and MES on TCD monitoring were selected from an ischemic stroke registry. Patients with prosthetic valves or cerebral/carotid artery stenosis were excluded. RESULTS: By TCD monitoring of 30 patients, 78 MES were detected: 47 on the right and 31 on the left side (60.3% vs. 39.7%, p < 0.01, chi-square test). Among 21 patients who had middle or anterior cerebral artery (MCA/ACA) territory infarcts, 16 had right-side-dominant infarcts and 5 patients had left-side-dominant infarcts (76.2% vs. 23.8%, p < 0.01, chi-square test). The median infarct volume on the right side was 16.2 (3.18-75.4) ml, while that of left side was 1.2 (0.25-5.05) ml (p < 0.01, Mann-Whitney U test). CONCLUSION: This study demonstrated the existence of a right-side propensity of cardiogenic emboli and the larger infarct volume of right-side MCA/ACA stroke in patients with AF. These results can be attributed to anatomical differences between the innominate and the left common carotid artery.