Right-to-left shunt detection using contrast-enhanced transcranial Doppler: A comparison of provocation maneuvers between coughing and a modified Valsalva maneuver

• Published in: PloS one Vol. 12; no. 4; p. e0175049
• Main Authors: Wang, Si-Bo, Wang, Xiao-Cong, Ma, Yan, Liu, Kang-Ding, Xing, Ying-Qi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.04.2017; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Age; Aged; Analysis; Aneurysms; Biology and Life Sciences; Bivariate analysis; Blood flow; Blood pressure; Cardiology; Cerebral blood flow; Circulation; Classification; Clinical trials; Colleges & universities; Comparative analysis; Coronary artery disease; Cough; Decompression; Decompression sickness; Delineation; Diagnosis; Doppler effect; Echocardiography; Embolism; Etiology; Expiration; Female; Flow velocity; Guidelines; Headache; Headaches; Health care; Heart; Heart diseases; Hospitals; Humans; Injection; Ischemia; Lesions; Lung diseases; Male; Maneuvers; Medical instruments; Medical personnel; Medicine and Health Sciences; Mercury; Middle Aged; Migraine; Nervous system; Neurology; Neurosciences; Obstructive lung disease; Quality control; Research and Analysis Methods; Risk factors; Sensitivity; Septum; Stroke; Syringes; Technicians; Tension; Therapy; Transcranial Doppler ultrasonography; Transient ischemic attack; Ultrasonic imaging; Ultrasonography, Doppler, Transcranial - methods; Ultrasound; Valsalva exercise; Valsalva Maneuver; Valsalva's maneuver; Velocity curve; Young Adult; Zinc
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0175049

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.