Role Of Cardiac CT To Assess The Left Atrial Appendage For The Management Of Atrial Fibrillation And Concomitant Cardioembolic Stroke

Atrial fibrillation(AF)and concomitant cardioembolic stroke are the most common problems stumble upon in clinical practice.In recent past,there has been significant progress in techniques and diagnostic tools aidingthe diagnosis and treatment of AF and concomitant cardioembolic stroke.Catheter ablation has gradually come out as the therapy of choice for symptomatic,recurrent,drug refractory AF.Progressing techniques in catheter ablation of AF have led to the extension of the knowledge of left atrium anatomy.The left atrial appendage(LAA)is understood to be the key location of thrombus formation,mostly in patients with nonvalvular AF.Preprocedural diagnosis of LAA thrombus is essential because the existence of thrombus is an absolute contraindication for ablation procedures in patients with AF due to the concomitant risk of thromboembolic phenomenon.Transesophageal echocardiogram(TEE)is regarded the gold standard modality in detecting LAA thrombi.However,this is a semi-invasive procedure with rare but potential life-threatening complications.Cardiac Computed Tomography(CCT)is an explicit,noninvasive substitute to TEE for the detection of LAA thrombi,mainly when delayed imaging acquisition protocols are used.During the past decade,CCT has been tested for the detection of LAA thrombi using several imaging protocols and results are noteworthy.CCT is also of primary significance during setting of LAA closure devices and several electrophysiological studies.However,CCT also have some limitations.Large,multicenter studies are neededto further clear up the role of CCT in assessment of LAA.More focus should be given in reducing radiation dose and use of iodinated contrast.The purpose of this article is to explore the potential use of CCT and highlight the data which are indicative of their efficacy assessing the LAA.We will also shed light on anatomical,physiological and the pathophysiological aspect of LAA.We will also compare CCT with other imaging modalities used for assessment of LAA and point out benefits and limitations of CCT.