title: A detailed description and assessment of outcomes of patients with hospital recorded QTc prolongation.
abstract: Corrected QT (QTc) interval prolongation has been shown to be an independent predictor of mortality in many clinical settings and is a common finding in hospitalized patients. The causes and outcomes of patients with extreme QTc interval prolongation during a hospital admission are poorly described. The aim of this study was to prospectively identify patients with automated readings of QTc intervals >550 ms at 1 academic tertiary hospital. One hundred seventy-two patients with dramatic QTc interval prolongation (574 ± 53 ms) were identified (mean age 67.6 ± 15.1 years, 48% women). Most patients had underlying heart disease (60%), predominantly ischemic cardiomyopathy (43%). At lease 1 credible and presumed reversible cause associated with QTc interval prolongation was identified in 98% of patients. The most common culprits were QTc interval-prolonging medications, which were deemed most responsible in 48% of patients, with 25% of these patients taking ≥2 offending drugs. Two patients were diagnosed with congenital long-QT syndrome. Patients with electrocardiograms available before and after hospital admission demonstrated significantly lower preadmission and postdischarge QTc intervals compared with the QTc intervals recorded in the hospital. In conclusion, in-hospital mortality was high in the study population (29%), with only 4% of patients experiencing arrhythmic deaths, all of which were attributed to secondary causes.
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada. Electronic address: zlaksman@uwo.ca.
authors: Zachary
authors: Z
authors: Laksman
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Bogdan
authors: B
authors: Momciu
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: You Won
authors: YW
authors: Seong
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Patricia
authors: P
authors: Burrows
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Susan
authors: S
authors: Conacher
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Jaimie
authors: J
authors: Manlucu
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Peter
authors: P
authors: Leong-Sit
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Lorne J
authors: LJ
authors: Gula
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Allan C
authors: AC
authors: Skanes
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: Raymond
authors: R
authors: Yee
authors: Division of Cardiology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors: George J
authors: GJ
authors: Klein
authors: Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada.
authors: Andrew D
authors: AD
authors: Krahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D007297:Inpatients; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D055815:Young Adult