Abstract WP410: Comparison of Transcranial Doppler Ultrasound with Intracardiac Echocardiography in the Detection of Cardiac Right-to-Left shunt in Children and Young Adults
Background and Objectives: Right to left shunts (RLS) found with patent foramen ovale are implicated in the pathophysiology of cryptogenic stroke, migraine headaches as well as decompression illness. Our dysautonomia clinic has described a syndrome of neurocardiogenic syncope, stroke, migraine headaches and positive tilt table testing associated with atrial septal defects (ASD). All patients underwent transcranial Doppler ultrasound (TCD) and intracardiac echocardiogram (ICE) testing.
Methods: We performed a restrospective analysis of a prospectively obtained registry of patients that underwent shunt testing ± endovascular ASD closure. All patients had previously undergone a transthoracic echocardiogram bubble study (TTE) to confirm a RLS. Patients underwent general anesthesia and bilateral TCD monitoring of the middle cerebral artery. Valsalva was produced by the anesthesiologist (40mm Hg). Simultaneous assessment of RLS was performed using ICE and TCD monitoring after injection of agitated saline into the femoral vein sheath. If negative, a direct right atrial injection was performed. The size of ASD was measured by ICE independent of TCD results.
Results: Between 9/2010 and 7/2012, 112 patients underwent testing. Patient characteristics are displayed in the table. RLS was found in 82.1, 81.1, and 71.4% by TTE, ICE and TCD, respectively. After peripheral injection (n=85), when compared to ICE, TCD had a sensitivity, specificity, PPV, NPV and accuracy of 96, 100, 100, 64 and 95%, respectively. Combined peripheral and intracardiac injections (N=112) when compared to ICE, TCD had a sensitivity, specificity, PPV, NPV and accuracy of 89, 100, 100, 66 and 90%, respectively.
Conclusion: Transcranial Doppler ultrasound detection of right to left shunts remains a highly accurate, non-invasive tool. If closure of cardiac shunts is proven to prevent stroke, migraines or treat neurocardiogenic syncope, TCD might be considered the preferred screening method.
- © 2012 by American Heart Association, Inc.