Cardiac Imaging After Ischemic Stroke or Transient Ischemic Attack

Abstract

Purpose of review: Cardiac imaging after ischemic stroke or transient ischemic attack (TIA) is used to identify potential sources of cardioembolism, to classify stroke etiology leading to changes in secondary stroke prevention, and to detect frequent comorbidities. This article summarizes the latest research on this topic and provides an approach to clinical practice to use cardiac imaging after stroke.

Recent findings: Echocardiography remains the primary imaging method for cardiac work-up after stroke. Recent echocardiography studies further demonstrated promising results regarding the prediction of non-permanent atrial fibrillation after ischemic stroke. Cardiac magnetic resonance imaging and computed tomography have been tested for their diagnostic value, in particular in patients with cryptogenic stroke, and can be considered as second line methods, providing complementary information in selected stroke patients. Cardiac imaging after ischemic stroke or TIA reveals a potential causal condition in a subset of patients. Whether systematic application of cardiac imaging improves outcome after stroke remains to be established.

Keywords: Computed tomography; Echocardiography; Embolism; Ischemic stroke; Magnetic resonance imaging; Transient ischemic attack.

Fig. 1

Schematic presentation of the most frequent sources for cardiovascular embolism. a The most common localization of LV thrombi, usually the result of regional akinesia due to a previous myocardial infarction, is the LV apex, which is ideally visualized on the apical 4-chamber view of the TTE. b Typical presentation of a LAA thrombus on a TEE mid-esophageal 2-chamber view at about 90°. c Transthoracic apical 4-chamber-view demonstrating the pronounced dilation of the left ventricle in case of a dilated cardiomyopathy (left) and the multiple prominent ventricular trabeculations with intertrabecular spaces seen in non-compaction cardiomyopathy (right). d The usually valve associated papillary fibroelastoma (PFE) and myxoma, typically located in the atria, are the most common primary cardiac tumors in adults, which are both associated with a high risk of embolism (TTE parasternal long-axis view). e Bubble transition from the right to the left atrium (positive “bubble test”) in case of a patent foramen ovale documented using a TEE mid-esophageal bicaval view at about 110°. f Vegetations, a main criterion for endocarditis (here mitral valve endocarditis diagnosed in a mid-esophageal longitudinal axis view of the left ventricle at about 120° in the TEE examination; left), and prosthetic valves (here double-wing prosthesis of the mitral valve shown in a parasternal longitudinal axis view of the TTE; right) are further potential sources of cardioembolism. gAortic atheroma ≥ 4 mm have been associated with ischemic stroke and can be detected during retraction of the TEE probe at the end of the examination (here mid-esophageal short (left) and long (right) axis view of the ascending aorta). Ao aorta, IVC inferior vena cava, LA left atrium, LAA left atrial appendage, LV left ventricle, LVOT left ventricular outflow tract, (M/R) PA (main/right) pulmonary artery, RA right atrium, RV right ventricle