Support WBURWhy Doctors Keep Monitoring Children Who Recover From Mysterious COVID-Linked IllnessPlay04:51Download AudioFred MogulMaria GodoyJuly 15, 2020 ShareMarcelina Alvarez, a technician at Montefiore Medical Center in the Bronx, administers an EKG to Israel Shippy to check the functioning of his heart. (Fred Mogul/ WNYC)