Role of echocardiography in patients with stroke

Abstract

Investigation of potential embolic source is an important diagnostic step in treating patients with ischemic stroke and transient ischemic attack. Cardiogenic embolism has been estimated to be the causative factor in 15-30% of all cases of ischemic stroke. Cardioembolic strokes are generally severe and recurrence and mortality rate high. Various cardiac disorders including atrial fibrillation, ventricular thrombus, valvular heart disease, cardiac tumors, and structural heart defects can cause cardioembolic stroke. Although the aortic arch is not a cardiac structure, it is usually considered under source of cardiac embolism (cardioaortic source) and is reviewed in this article. Echocardiography (both transthoracic and transesophageal) is a widely used and versatile technique that can provide comprehensive information of thromboembolic risk in patients with stroke. This article reviews potential cardiac sources of stroke and discusses the role of echocardiography in clinical practice.

Established and potential echocardiographic markers of embolism and their therapeutic implications in patients with ischemic stroke

“…In the Stroke Prevention in Atrial Fibrillation (SPAF) III and other trials, LAA thrombi, dense spontaneous echo contrast, LAA peak flow velocities 20 cm/s, and complex aortic plaques were independently associated with increased thromboembolic risk in AF patients [11].…”

“…From 1% to 2.5% of patients with acute MI suffer a stroke within 4 weeks, one-half in the first 5 days. LV thrombus was more likely in patients with EF of < 40%, anterior wall MI and LV aneurysm [11]. Embolic events are estimated to occur in 4% of patients with DCM who have a LVEF ≤ 35%.…”

“…Moreover, the elderly population of today has a higher prevalence of predisposing conditions for AF, such as diabetes, heart failure, hypertension, and coronary heart disease [10]. Newly detected AF is identified in 10% of the patients who experience a stroke or a transient ischemic attack, and an additional 11% cases of AF are newly detected when patients undergo 30 days of continuous electrocardiographic monitoring [11].The left atrial appendage (LAA) is the major site of thrombus formation in non-valvular AF.…”

“…Transesophageal echocardiography (TEE) is considered to be the gold-standard technique to detect LAA thrombi, with values of sensitivity and specificity approaching 99% [11].…”

Assessment of left atrial appendage function by transthoracic pulsed Doppler echocardiography: Comparing against transesophageal interrogation and predicting echocardiographic risk factors for stroke

“…In contrast, transthoracic echocardiography (TTE) is noninvasive, readily available, and more widely used. Patients with AF often have TTE in their initial workup to detect any structural pathology associated with AF . TTE is also commonly used to screen for intracardiac shunt and thrombus in patients presenting with suspected embolic stroke, regardless of the cardiac rhythm .…”