Relation Between Patent Foramen Ovale and Cryptogenic Stroke: Single-center Echocardiographic Study

Abstract

Objective: The transcatheter closure of patent foramen ovale (PFO) has been proven effective in preventing cryptogenic stroke (CS), and it is necessary to determine the structure of PFO associated with CS. In this study, we sought to evaluate the characteristics of PFO by using transesophageal echocardiography (TEE) and contrast transesophageal echocardiography (c-TEE) to assess the characteristics of PFO associated with CS and seek out the high-risk factors for PFO for CS. Method: A total of 52 test patients who suffered CS combined with PFO and 64 control patients diagnosed with PFO without stroke were enrolled. The structure of the PFO was observed by TEE and c-TEE. The differences in PFO structure between the test patients and controls were compared. Results: The patients in the test group were older than the controls. The height and length of the PFO during Valsalva were found to be greater in the test group than in the control group. The occurrence rates of low-angle PFO (angle between inferior vena cava and PFO ≤10°) and atrial septal aneurysm (ASA) were higher in the test group than in the control group. Right-to-left shunt (RLS) ≥ grade II during Valsalva was significantly higher in the test group than in the control group. Regarding RLS ≤ grade II during Valsalva and all grades of RLS at rest, there was no difference between the two groups. Multivariate analysis showed that the length of the PFO during Valsalva, the presence of ASA, large (≥ grade II) RLS shunt during Valsalva and low-angle PFO were independent relevant factors for CS. Conclusion: The length of the PFO tunnel, low-angle PFO, RLS III during Valsalva and the presence of ASA were associated with a greater risk for CS. TEE combined with c-TEE may be helpful in identifying PFO patients at great risk of CS and screening for transcatheter closure of PFO.

Keywords

• cryptogenic stroke
• echocardiography
• patent formane ovale