Atherosclerotic plaque in the descending aorta has emerged as a potential etiology of embolic stroke due to diastolic flow reversal in this region. This study seeks to investigate 1) whether aortic stiffness assessed by pulse wave velocity (PWV) may be related to flow reversal and 2) the effects of medical therapy on PWV and flow reversal. Twenty cryptogenic stroke patients were included in this 4D flow MRI study. We found relationships between age, PWV and flow reversal. No systematic change in PWV or flow reversal was detected for patients taking medications with potential de-stiffening effects.