Comparative analysis of the diagnostic value of several methods for the diagnosis of patent foramen ovale.

The aim of this research was to compare the sensitivity and positive predictive value of contrast transcranial Doppler (c-TCD), contrast transthoracic echocardiography (c-TTE), and contrast transesophageal echocardiography (c-TEE), to determine the best method for diagnosing patent foramen ovale (PFO) and to provide a reference for the further improvement of clinical practice. We investigated 161 patients who suffered from migraines, cryptogenic stroke, TIA, and cerebral infarction of unknown cause. All patients underwent transcatheter examination, and the results of the right heart catheterization (RHC) were considered the gold standard for PFO diagnosis. The present study revealed that c-TTE with the Valsalva maneuver had a higher sensitivity in detecting PFO related right-to-left shunt (PFO-RLS), c-TCD performed similarly to c-TEE but maybe produce more false positives. Moreover, when we observed color shunt from the slit-like channel between the septum primum and the septum secundum on TEE, the positive predictive value was the highest. Patients with suspected PFO should be examined with c-TTE and c-TEE for confirmation. When there were a large number of bubbles in the left heart, especially in the presence of color shunt, the positive predictive value was the highest. The positive results of c-TCD only point out the presence of right-to-left shunt and cannot exclude extracardiac shunt, so c-TCD should not be used as a screen for PFO, additional measures such as c-TTE and c-TEE should be used.