Table 4.

Comparison of RLS Quantification With ICE Versus TCD

Condition	ICE Grade ≥1	TCD Grade ≥2	RLS Shunt Underestimated by ICE	RLS Shunt Underestimated by TCD	p 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.