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Munchausen syndrome by proxy is a difficult to diagnose, complex form of child abuse. The subtleties of this type of abuse allow the parent to victimize the child by presenting a fictitious medical history, which then initiates a series of unnecessary diagnostic procedures and therapeutic interventions. By recognizing the warning signals of this syndrome health-care professionals can intervene, and prevent its potentially fatal results. [ABSTRACT FROM AUTHOR]

Background: Nearly 40% of patients with long QT syndrome (LQTS) can have a nondiagnostic QTc at rest. Treadmill and cycle exercise stress testing are used in the diagnostic evaluation of LQTS., Objective: The purpose of this study was to determine the diagnostic significance of peak exercise and recovery phase QTc values during treadmill stress testing in LQTS., Methods: An Institutional Review Board-approved, retrospective analysis was performed on the treadmill stress tests in 243 patients including 82 LQT1, 55 LQT2, 18 LQT3, and 88 genotype-negative patients dismissed as normal. Blinded to genotype, QTc was calculated at rest, peak exercise, and 1, 2, 3, 4, and 5 minutes of recovery., Results: Compared with those dismissed as normal, the average QTc was greater at all scored stages in LQT1 and LQT3 patients and at all stages in LQT2 patients except peak exercise and 1 minute of recovery (P < .01). Either an absolute QTc ≥ 460 ms during the recovery phase or a maladaptive, paradoxical increase in QTc, defined as QTc recovery--QTc baseline ≥ 30 ms (ΔQTc), distinguished patients with either manifest or concealed LQT1 from all other subsets (P < .0001). The presence of beta-blockers did not blunt these abnormal repolarization profiles., Conclusion: Treadmill stress testing can unmask patients with concealed LQTS, particularly LQT1, with good diagnostic accuracy., (Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)