1. Department of Neurology and Neurological Sciences (D.K.L., A.S., N.S.), Stanford University, Palo Alto, CA.
2. Department of Pediatrics-Cardiology (J.P.W.), Stanford University, Palo Alto, CA.
3. Department of Radiology/Cardiovascular Imaging (J.S.), Stanford University, Palo Alto, CA.
4. Department of Pediatrics, Division of Cardiology, University of Kentucky, Lexington (R.T.C.).