Inter-Relationship Between Electrocardiographic Left Ventricular Hypertrophy and QT Prolongation as Predictors of Increased Risk of Mortality in the General Population

• Type of Material: Article
• Authors: Elsayed Z. Soliman, Wake Forest School of Medicine; Amit J. Shah, Emory University; Andrew Boerkircher, Wake Forest Baptist Medical Center; Yabing Li, Wake Forest School of Medicine; Pentti Rautaharju, Wake Forest School of Medicine
• Language: English
• Date: 2014-06-01
• Publisher: American Heart Association
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 American Heart Association, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1161/CIRCEP.113.001396
• Title of Journal or Parent Work: Circulation: Arrhythmia and Electrophysiology
• ISSN: 1941-3149
• Volume: 7
• Issue: 3
• Start Page: 400
• End Page: 406
• Grant/Funding Information: This work was supported, in part, by the National Center for Advancing Translational Sciences of the National institutes of Health under Award Number UL1TR000454 and KL2TR000455 to Dr Shah.
• Keywords: electrocardiography; MYOCARDIUM; Cardiovascular System & Cardiology; SOCIETY; prolonged QT; left ventricular hypertrophy; CONDUCTION; Life Sciences & Biomedicine; DURATION; CRITERIA; Science & Technology; CARDIOMYOPATHY; HEART-DISEASE; Cardiac & Cardiovascular Systems; HYPERTENSIVE PATIENTS; SUDDEN CARDIAC DEATH; INTERVAL
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Medicine and Surgery

Abstract

Background-Prolonged-QT commonly coexists in the ECG with left ventricular hypertrophy (ECG-LVH). However, it is unclear whether to what extent QT prolongation coexisting with ECG-LVH can explain the prognostic signifcance of ECG-LVH, and whether prolonged-QT coexisting with ECG-LVH should be considered as an innocent consequence of ECG-LVH. Methods and Results-The study population consisted of 7506 participants (mean age, 59.4±13.3 years; 49% whites; and 47% men) from the US Third National Health and Nutrition Examination Survey. ECG-LVH was defned by Cornell voltage criteria. Prolonged heart-rate-adjusted QT (prolonged-QTa) was defned as QTa≥460 ms in women or 450 ms in men. Cox proportional hazards analysis was used to calculate the hazard ratios with 95% confdence intervals for the risk of all-cause mortality for various combinations of ECG-LVH and prolonged-QTa. ECG-LVH was present in 4.2% (N=312) of the participants, of whom 16.4% had prolonged-QTa. In a multivariable-adjusted model and compared with the group without ECG-LVH or prolonged-QTa, mortality risk was highest in the group with concomitant ECG-LVH and prolonged-QTa (hazard ratio, 1.63; 95% confdence interval, 1.12-2.36), followed by isolated ECG-LVH (1.48; 1.24-1.77), and then isolated prolonged-QTa (1.27; 1.12-1.46). In models with similar adjustment where ECG-LVH and prolonged-QTa were entered as 2 separate variables and subsequently additionally adjusted for each other, the mortality risk was essentially unchanged for both variables. Conclusions-Although prolonged-QT commonly coexists with LVH, both are independent markers of poor prognosis. Concomitant presence of prolonged-QT and ECG-LVH carries a higher risk than either predictor alone.