Table 1.

Criteria for diagnosis of embolic stroke of undetermined source (ESUS).^a

1. Ischaemic stroke detected by CT or MRI that is not lacunar.b

2. Absence of extracranial or intracranial atherosclerosis causing >50% luminal stenosis in arteries supplying the area of ischaemia.

3. No major-risk cardioembolic source of embolism.c

4. No other specific cause of stroke identified (e.g. arteritis, dissection, migraine/vasospasm, drug abuse).

^aRequires minimum diagnostic evaluation that includes cardiac rhythm monitoring for >24 h with automated rhythm detection.¹

^bLacunar defined as a subcortical infarct <1.5 cm (<2.0 cm on MRI diffusion images) in largest dimension, including on MRI diffusion-weighted images, and in the distribution of the small, penetrating cerebral arteries of the cerebral hemispheres and pons.

^cPermanent or paroxysmal atrial fibrillation, sustained atrial flutter, intracardiac thrombus, prosthetic cardiac valve, atrial myxoma or other cardiac tumours, mitral stenosis, recent (<4 weeks) myocardial infarction, left ventricular ejection fraction <30%, valvular vegetations or infective endocarditis.

CT: computed tomography; MRI: magnetic resonance imaging.