Table 4

Comparison of RLS Quantification With ICE Versus TCD

ConditionICE Grade ≥1TCD Grade ≥2RLS Shunt Underestimated by ICERLS Shunt Underestimated by TCDp Value
Pre-deployment Valsalva maneuver (n = 31)30/31 (97%)30/31 (97%)1/31 (3%)1/31 (3%)>0.99
Post-deployment rest (n = 30)6/30 (20%)11/30 (37%)5/30 (17%)0/30 (0%)0.063
Post-deployment Valsalva maneuver/manometer (n = 29)16/29 (55%)25/29 (86%)10/29 (34%)1/29 (3%)0.012

An ICE grade ≥1 or a Spencer TCD grade ≥2 was assumed to represent a significant shunt. Before closure, when there was a large RLS, ICE and TCD had comparable rates of detecting significant RLS. After device closure, when there was diminished RLS, ICE underestimated the amount of RLS after device deployment in 5 patients (17%) at rest and 10 patients (34%) during the Valsalva or manometer maneuvers. The ICE images were not available for analysis on 5 patients, ICE was not performed on 1 patient, and post-closure bubble study was not performed on 1 patient (all excluded from this analysis); post-deployment ICE was not performed on 2 patients, post-deployment provocative maneuvers were not performed on 1 patient.

ICE = intracardiac echocardiography; RLS = right-to-left shunt; TCD = transcranial Doppler.