Introduction and objective: Patent foramen ovale has been associated with stroke in young patients with cryptogenic stroke. The purpose of this study is to examine the prevalence of patent foramen ovale in this group of patients, as well as their anatomical and functional characteristics by contrast echocardiography, trying to determine ictus risk markers in young patients with acute ischemic stroke.
Patients and method: Prospective study of 90 patients under the age of 50 who were hospitalised consecutively due to a clinical presentation suggestive of stroke. No cause was found in 55 out of 90 (group I) and the rest, in which an stroke was finally disregarded, were used as the control group (group II). A transthoracic and transesophageal echocardiography examination with 2 types of contrast agents was performed in all patients to determine the presence of a patent foramen ovale and its anatomical and functional characteristics.
Results: Patent foramen ovale was observed more frequently in group I than in group II (43 versus 21%; p < 0.05). Among patients with a patent foramen ovale those with an ischemic stroke showed greater mobility of the oval membrane, more frequent large shunts of contrast in a single frame in the left heart, and more frequent shunts at rest. Transesophageal echocardiography without contrast showed a high sensitivity (90%) and specificity (93%) for detecting anatomically permeable foramen ovale whereas contrast transthoracic echocardiography showed a low sensitivity (13%). There were no differences between the two contrasts used.
Conclusions: Near half of young patients with ischemic stroke of an unknown origin have a patent foramen ovale. A bigger mobility of the membrane of the oval cavity and a large degree of shunt contrast as well as shunt at rest detected by contrast transesophageal echocardiography, seem to identify patent foramen ovale patients with ischemic stroke. In these patients, transthoracic echocardiography has low sensibility for detecting permeability of the foramen ovale.