title: Right-to-left shunt detection using contrast-enhanced transcranial Doppler: A comparison of provocation maneuvers between coughing and a modified Valsalva maneuver.
abstract: Contrast-enhanced transcranial Doppler (c-TCD) has been used to detect right-to-left shunts (RLS) because it is highly sensitive and cost-effective. The use of provocation maneuvers, such as physiologic maneuvers (e.g., coughing) and the Valsalva maneuver (VM) to transiently increase right atrial pressure and induce RLS increases the sensitivity of RLS detection. In this study, we sought to determine whether coughing is as effective as the VM in aiding the detection of RLS. We evaluated 162 subjects for RLS, using c-TCD under three different conditions: (i) resting state, (ii) coughing, and (iii) modified VM (m-VM), which involved blowing into a tube connected to a sphygmomanometer at 40 mmHg for 10 s. The positive rate of RLS detection with the m-VM was significantly higher than that with coughing. In addition, a difference between the two maneuvers was observed in terms of the degree of RLS seen. The m-VM should be widely used to detect RLS, because it is reliable, standardized, and cost-effective.
authors.affiliation: Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.
authors.forename: Si-Bo
authors.initials: SB
authors.lastname: Wang
authors.affiliation: Department of Echocardiography, Cardiovascular Center, The First Hospital of Jilin University, Changchun, China.
authors.forename: Xiao-Cong
authors.initials: XC
authors.lastname: Wang
authors.affiliation: Department of Echocardiography, Cardiovascular Center, The First Hospital of Jilin University, Changchun, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.
authors.forename: Kang-Ding
authors.initials: KD
authors.lastname: Liu
authors.affiliation: Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.
authors.forename: Ying-Qi
authors.identifier: http://orcid.org/0000-0001-8944-4836
authors.initials: YQ
authors.lastname: Xing
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003371:Cough; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014636:Valsalva Maneuver; D055815:Young Adult