Impact of blood flow volume in determining the destination of intracardiac thrombi using computational fluid dynamics

Atrial fibrillation (AF) induces cardioembolic stroke due to intracardiac fibrin thrombus formation. Although it is well established that a cardioembolic stroke affects the anterior circulation more frequently than it affects the posterior circulation, the destination where the thrombi migrate when cardioembolic stroke occurs in each patient remains unclear. We present a critical case wherein a bilateral internal carotid artery (ICA) territory infarction was diagnosed in a patient with AF who apparently developed nearly simultaneous occlusion in the ICAs bilaterally. A 92-year-old woman with AF who appeared to have developed bilateral occluded common carotid artery (CCA)-ICAs almost simultaneously presented after the sudden onset of coma and quadriplegia and was diagnosed with bilateral ICA territory infarction. The patient died at 4 days after the onset due to the huge infarction. The blood flow in the aorta and the major branches of the aortic arch were examined using computational fluid dynamics (CFD) based on contrast-enhanced computed tomography angiography, which revealed that the right and left CCAs covered larger flow volumes than the other aortic arch branches, suggesting that the intracardiac thrombi migrated into the bilateral CCA-ICAs in the patient. The study findings imply that the fluid dynamic factors of major branches from the aortic arch can be one of the decisive factors for intracardiac thrombus distribution. CFD could simulate patient-specific hemodynamics and may be useful to investigate the susceptibility of the aortic arch branches to occlusion by AF-induced intracardiac emboli.