Intracranial embolism characteristics in PFO patients: A comparison between positive and negative PFO by transesophageal echocardiography The rule of nine (original) (raw)

Background and purpose: Patent foramen ovale (PFO) can be diagnosed by contrast-enhanced transcranial Doppler (cTCD), but no definitive criteria exist to correlate the results obtained from cTCD with diagnoses of PFO obtained by contrast-enhanced transesophageal echocardiography (cTEE). The aim of the present study was to analyze markers in the positive RLS by cTCD that confirm the PFO by cTEE. Methods: Twenty-six stroke patients who had previously submitted to cTEE, 16 with PFO (PFO group) and 10 without PFO (no-PFO group), were evaluated for three markers based on a positive cTCD test. The number of microembolic signs (MES), the latency time (LT) to the first MES and the duration time (DT) of MES were evaluated to look for a difference between the PFO and no-PFO group. Results: The PFO group had higher MES (80.9 ± 124.5 vs. 10.2±25.6, p b 0.001), shorter LT (12.5 ± 6.6 vs. 16.2 ± 5.1, p = 0.02) and longer DT (21.4 ± 17.4 vs. 11.7 ± 12.5, p = 0.013) compared with the no-PFO group. Considering only MCA tests with more than 9 MES and LT shorter than 9 s, 30% of patients from the PFO group had positive tests compared with no patients from the no-PFO group. This cutoff demonstrates a specificity and positive predictive value of 100%. Conclusions: The rule of nine (N 9 MES and LT b 9 s) for cTCD can be considered a marker for PFO diagnosis by cTEE.