Background: The eustachian valve (EV) (valvula venae cavae inferioris) is a remnant of the embryonic right valve of the sinus venosus. Embryologically, the EV directs oxygenated blood from the inferior vena cava across the patent foramen ovale (PFO) into the systemic circulation. Transthoracic echocardiography shows the EV in the majority of newborns, but the prevalence of EV in adults studied with transesophageal echocardiography is unknown. We studied whether the presence of an EV is associated with PFO or with cryptogenic stroke.
Methods: The frequency and size of the EV was studied in 211 consecutive patients undergoing transesophageal echocardiography after a cryptogenic stroke and in 95 consecutive patients without cerebrovascular events. In all 306 patients, the presence of a PFO was studied with 2-dimensional transesophageal echocardiographic, color Doppler, and contrast echocardiographic studies.
Results: An EV was seen in 174 of 306 patients overall (57%). The mean size was 1.0 +/- 0.4 cm (range: 0.5-2.0); 70% of patients with an EV had a PFO (Cohen's kappa = 0.75; P <.001). This relationship was not significantly influenced by a cryptogenic stroke. The prevalence of PFO was 30% in the control group and 61% for those with presumed paradoxical embolism (P <.001). Thus, an EV was more common for patients with presumed paradoxical embolism than in control patients (143 of 211 68% vs 31 of 95 33%, respectively, P <.001). There was no significant difference in the size of the EV between the 2 groups (1.1 vs 1.0 cm; P =.24).
Conclusion: A persisting EV is a frequent finding in patients with a PFO. By directing the blood from the inferior cava to the interatrial septum, a persisting EV may prevent spontaneous closure of PFO after birth and may, therefore, indirectly predispose to paradoxical embolism.