Was your mother right--do we always need to close the door?

Abstract

Stroke remains one of the most feared and devastating complications for patients to envisage. This remains true regardless of the age of the patient and the presence or absence of comorbidities, but it may be relatively more important the younger the patient is. Establishing the pathogenesis of stroke is fundamentally important for attempts at prevention. In some patients, the diagnosis of the underlying cause is relatively straightforward—eg, the presence of a high-grade, ulcerated lesion in the carotid artery in the distribution of the central nervous system symptoms or neurological deficit. In other cases, it may be considerably more difficult; then, the question of a cardiac source is often raised. See p 1121 Echocardiography has become an integral part of the evaluation in many such patients. Early in the history of this field, attention was focused on the left atrial appendage as a putative source. In addition, however, abnormalities of the atrial septum were documented and have since come to occupy an important position. These abnormalities were further characterized after the introduction of contrast studies and transesophageal echocardiography, which helped in the documentation of patent foramen ovale (PFO), atrial septal aneurysm (ASA), and right-to-left shunt. In such patients, emboli potentially could pass from the venous to the systemic arterial circulation.1,2⇓ It must be remembered that there may be other mechanisms, including thrombus forming in the ASA or thrombus from supraventricular arrhythmias. In a recent meta-analysis,3 there were 2738 references of case-control studies that identified the keywords PFO, ASA, or right-to-left shunt. In this meta-analysis, combined odds ratios were calculated with the use of both fixed and random-effect methods. There are several important issues that can be addressed, including: (1) the frequency of each of these conditions in control populations versus patients with cryptogenic stroke or stroke of known …