[1] Stanford Univ, Stanford Hosp & Clin, Dept Pediat, Palo Alto, CA 94304 USA
[2] Stanford Univ, Stanford Hosp & Clin, Dept Anesthesiol, Palo Alto, CA 94304 USA
[3] Stanford Univ, Sch Med, Palo Alto, CA 94304 USA
[4] Stanford Univ, Sch Med, Dept Cardiothorac Surg, Div Pediat Cardiac Surg, Palo Alto, CA 94304 USA
[5] Stanford Univ, Sch Med, Dept Pediat, Div Pediat Cardiol, Palo Alto, CA 94304 USA
[6] Univ Calif San Diego, Dept Pediat, Sch Med, Div Pediat Cardiol, San Diego, CA 92103 USA