No clot, no problem? not exactly

SESSION TITLE: Imaging in Cardiovascular CasesSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/18/2022 12:25 pm - 01:25 pmINTRODUCTION: Atrial stunning is a transient mechanical dysfunction of the left atrium (LA) and left atrial appendage (LAA) related to cardioversion. Left atrial stunning is associated with up to 53% reduction in LAA blood flow velocities and appearance of spontaneous echo contrast (SEC) in 80% of the patients with conversion to sinus rhythm post-cardioversion [1].CASE PRESENTATION: A 92-year-old woman (weight 58.1 kg) with a history of chronic kidney disease Stage IIIb (creatinine 1.5 mg/dL) and symptomatic paroxysmal atrial fibrillation (CHA₂DS₂-VASc score 3) on dose reduced apixaban presented for an elective transesophageal echocardiogram (TEE) and external direct current cardioversion (DCCV). TEE showed preserved LV systolic function without valvular disease. The LA was dilated without findings of left atrial thrombus. The LAA was dilated, SEC was present with diminished exit velocity < 20 cm/s, and no thrombus was noted. The patient underwent successful cardioversion of atrial fibrillation to sinus rhythm. Unfortunately, hours later the patient developed severe right-sided extremity and left-sided facial weakness. CT angiography of head and neck showed a completely occluded left internal carotid artery (LICA). MRI of head and neck showed a large infarct of the left middle cerebral artery. The patient underwent emergent aspiration thrombectomy with extraction of a thrombus measuring 1.2 cm and total vessel recanalization. The patient had partial neurological recovery requiring extensive rehabilitation care.DISCUSSION: Atrial fibrillation has a strong association with larger LA and LAA sizes as well as reduced LAA blood flow velocities. All methods of cardioversion (transthoracic electrical, internal electrical, pharmacological and spontaneous) results in some degree of left atrial stunning and LAA dysfunction. The prevalence of LAA thrombus and relative risk of ischemic stroke is 2.6 times higher when peak LAA velocity is < 20 cm/s [2]. Appearance of SEC also has a strong association with reduced peak LAA velocities per Fatkin et al [3]. It is important to recognize the importance of echocardiographic parameters such as peak LAA blood flow velocities and appearance of SEC in the absence of thrombus even in an anticoagulated patient prior to cardioversion to minimize the risk of thromboembolic events post-cardioversion.CONCLUSIONS: This case highlights the significance of atrial stunning and the potential consequences. Paradoxical reduction of the blood flow in the LA and LAA is directly correlated with increased risk of thromboembolic events for hours to weeks post-cardioversion.Reference #1: Khan IA. Atrial stunning: basics and clinical considerations. Int J Cardiol. 2003;92(2-3):113-128. doi:10.1016/s0167-5273(03)00107-4Reference #2: Stroke Prevention In Atrial Fibrillation Investigators. The stroke prevention in atrial fibrillation III study: rationale, design, and patient features. J Stroke Cerebrovasc Dis. 1997;6(5):341-353Reference #3: Fatkin D, Kelly RP, Feneley MP. Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. J Am Coll Cardiol. 1994;23(4):961-969. doi:10.1016/0735-1097(94)90644-0DISCLOSURES: Consultant relationship with Siemens Medical Please note: 03/01/2021-Current Added 03/30/2022 by Nathaniel Dittoe, value=Grant/Research SupportNo relevant relationships by Akruti PrabhakarNo relevant relationships by EricsonJohn TorralbaNo relevant relationships by Damian Valencia SESSION TITLE: Imaging in Cardiovascular Cases SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 12:25 pm - 01:25 pm INTRODUCTION: Atrial stunning is a transient mechanical dysfunction of the left atrium (LA) and left atrial appendage (LAA) related to cardioversion. Left atrial stunning is associated with up to 53% reduction in LAA blood flow velocities and appearance of spontaneous echo contrast (SEC) in 80% of the patients with conversion to sinus rhythm post-cardioversion [1]. CASE PRESENTATION: A 92-year-old woman (weight 58.1 kg) with a history of chronic kidney disease Stage IIIb (creatinine 1.5 mg/dL) and symptomatic paroxysmal atrial fibrillation (CHA₂DS₂-VASc score 3) on dose reduced apixaban presented for an elective transesophageal echocardiogram (TEE) and external direct current cardioversion (DCCV). TEE showed preserved LV systolic function without valvular disease. The LA was dilated without findings of left atrial thrombus. The LAA was dilated, SEC was present with diminished exit velocity < 20 cm/s, and no thrombus was noted. The patient underwent successful cardioversion of atrial fibrillation to sinus rhythm. Unfortunately, hours later the patient developed severe right-sided extremity and left-sided facial weakness. CT angiography of head and neck showed a completely occluded left internal carotid artery (LICA). MRI of head and neck showed a large infarct of the left middle cerebral artery. The patient underwent emergent aspiration thrombectomy with extraction of a thrombus measuring 1.2 cm and total vessel recanalization. The patient had partial neurological recovery requiring extensive rehabilitation care. DISCUSSION: Atrial fibrillation has a strong association with larger LA and LAA sizes as well as reduced LAA blood flow velocities. All methods of cardioversion (transthoracic electrical, internal electrical, pharmacological and spontaneous) results in some degree of left atrial stunning and LAA dysfunction. The prevalence of LAA thrombus and relative risk of ischemic stroke is 2.6 times higher when peak LAA velocity is < 20 cm/s [2]. Appearance of SEC also has a strong association with reduced peak LAA velocities per Fatkin et al [3]. It is important to recognize the importance of echocardiographic parameters such as peak LAA blood flow velocities and appearance of SEC in the absence of thrombus even in an anticoagulated patient prior to cardioversion to minimize the risk of thromboembolic events post-cardioversion. CONCLUSIONS: This case highlights the significance of atrial stunning and the potential consequences. Paradoxical reduction of the blood flow in the LA and LAA is directly correlated with increased risk of thromboembolic events for hours to weeks post-cardioversion. Reference #1: Khan IA. Atrial stunning: basics and clinical considerations. Int J Cardiol. 2003;92(2-3):113-128. doi:10.1016/s0167-5273(03)00107-4 Reference #2: Stroke Prevention In Atrial Fibrillation Investigators. The stroke prevention in atrial fibrillation III study: rationale, design, and patient features. J Stroke Cerebrovasc Dis. 1997;6(5):341-353 Reference #3: Fatkin D, Kelly RP, Feneley MP. Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. J Am Coll Cardiol. 1994;23(4):961-969. doi:10.1016/0735-1097(94)90644-0 DISCLOSURES: Consultant relationship with Siemens Medical Please note: 03/01/2021-Current Added 03/30/2022 by Nathaniel Dittoe, value=Grant/Research Support No relevant relationships by Akruti Prabhakar No relevant relationships by EricsonJohn Torralba No relevant relationships by Damian Valencia