Discussion
We present a case of a 43-year-old female who had left posterior cerebral artery ischemia and an atrial septum aneurysm on echocardiography. An atrial septum becomes aneurysmal when an atrial dilated segment bulges at least 15 mm beyond the atrial septum’s surface level [4]. Atrial septal aneurysm and/or patent foramen ovale are thromboembolic heart defects. Both occur in 20% of the population and contribute to cryptogenic ischemic strokes in the younger population. Cryptogenic strokes are those with unknown or unexplained aetiologies [5]. Cerebrovascular events can occur in up to 52% of patients with atrial septum aneurysms. However, this significant incidence is found in patients with a clear cardiac thromboembolic cause of the cerebrovascular episode. The pathogenesis of stroke in people with atrial septum aneurysms is not completely known. It could be related to the production of direct thrombi at the atrial septum aneurysm [6]. Right-to-left paradoxical embolism of venous thrombi through a patent foramen ovale is another cause of cerebral embolism, as is the transition of a thrombus developed on the left atrial side of an aneurysm [5,7]. Transoesophageal echocardiography is commonly used to detect atrial septal aneurysms in individuals with unexplained strokes [8]. Our patient experienced cerebrovascular symptoms, but transthoracic echocardiography revealed only aneurysmal interatrial septum, no Patent Foramen ovale or another shunt, no intracardiac thrombus, or vegetation, ruling out several of the known potential explanations. However, because of the presence of bulbar cranial nerve palsy, we were unable to get a transoesophageal echo, which could have clarified the cause of the stroke. Possible underlying mechanisms include the formation of a thrombus on the aneurysm’s left atrial side or the development of interatrial fenestrations that resulted in a right-to-left shunt. Because hypertension has been linked to cryptogenic stroke, we believe it played a role in the aetiology of cryptogenic stroke in our patients [9]. Our case emphasizes the significance of atrial septum aneurysm as a potential risk factor for cryptogenic ischemic strokes. To the best of our knowledge, this is the first case of a symptomatic stroke patient with an atrial septal aneurysm on transthoracic echocardiography that does not have a patent foramen ovale or any other aetiology. More research is needed to determine the mechanism underlying such cerebrovascular events.