9 mo old boy with a h/o eczema, recurrent OM and 3 hospitalizations for pneumonia is admitted to the hospital for abnormalities on a routine blood test. on exam, he has numerous petechiae across his chest, abdomen and back. the labs show:

WBC 6.8, Hgb 11.3, HCT 34.1, Plt 12, Peripheral smear : small, rare platelets, Blood type A+, DAT neg.

Which treatment is most likely to be curative?

a 13 y/o obese male presents following an episode of chest pain after a 3 mile run that resolved after rest. He reports similar episode while playing soccer 1 mo ago. His family history includes an uncle who died suddenly of unknown causes in college. The patient's PE has a SEM at the left sternal border, louder with Valsalva, otherwise normal. EKG shows increased voltages in the precordial leads, left axis deviation, and deep Q waves in the interior and lateral leads. Next Best step?