title: Corrected QT interval (QTc) prolongation and syncope associated with pseudohypoparathyroidism and hypocalcemia.
abstract: An adolescent presented with exercise-associated syncope and electrocardiographic corrected QT interval (QTc) prolongation. Pseudohypoparathyroidism-induced hypocalcemia was diagnosed. The QTc (485 to 505 milliseconds) shortened during normalization of calcium levels, and syncope has not reoccurred.
authors.affiliation: Divisions of Cardiology and Endocrinology, and the Department of Pediatrics, University of Washington and Children's Hospital and Regional Medical Center, Seattle, WA 98105-0371, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Huang
authors.forename: F C
authors.initials: FC
authors.lastname: Cecchin
authors.forename: P
authors.initials: P
authors.lastname: Mahoney
authors.forename: M A
authors.initials: MA
authors.lastname: Portman
mesh_terms: D002648:Child; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000150:complications* / Q000503:physiopathology*; D008133:Long QT Syndrome / Q000209:etiology*; D011547:Pseudohypoparathyroidism / Q000150:complications* / Q000503:physiopathology*; D013575:Syncope / Q000209:etiology*