The distinct value of contrast transcranial Doppler and contrast transesophageal echocardiography in the diagnosis of patent foramen ovale

  AIM  To access the distinct values of contrast transcranial doppler (cTCD) and contrast transesophageal echocardiography (cTEE) in the diagnosis of right to left shunt (RLS)due to patent foramen ovale (PFO).

  METHODS  The results of 70 patients with PFO and receiving cTCD and cTEE were retrospectively analyzed.

  RESULTS  In all 70 patients, the shunt was detected at rest by cTCD in 67% and by cTEE in 43%. The positive results of 2 techniques with Valsalva maneuver (VM)was significantly improved. The rate of PFO-RLS detection of cTCD was significantly higher than cTEE (96% vs 83%; x² = 12.157, P < 0.05). The degree of semi-quantitative grading of cTCD was significantly higher than that of cTEE (Z = 40.211, P < 0.05). The degree of RLS show a linear increase with the PFO inner diameter (r = 0.701, P < 0.05). The degree of RLS show no significant correlation with the tunnel length of PFO (r = 0).

  CONCLUSION  cTCD and cTEE are complementary methods for diagnosis of PFO-RLS. The cTCD should be applied as the first choice for screening PFO owing to its good pike-up rate and noninvasion. The cTEE should be performed to accurately assess the morphologies of PFO when the closure is planned.