211 Acta Cardiol 2015; 70(2): 211-216 doi: 10.2143/AC.70.2.3073513 Address for correspondence: Soheila Talebi, M.D., 1901 1 st Avenue, New York, NY 10029, USA, Detrainment of Medicine. E-mail: Drs.Talebi@gmail.com Received 14 August 2014; revision accepted for publication 13 November 2014. INTRODUCTION The electrocardiogram (ECG) is an essential and most routinely performed clinical diagnostic tool 1-3 . Manual measurement of corrected QT interval (QTc) is a time- consuming and challenging task for primary care provid- ers, emergency department physicians, psychiatrists, and Underestimated and unreported prolonged QTc by automated ECG analysis in patients on methadone: can we rely on computer reading? Soheila TALEBI 1 , MD; Alaleh AZHIR 1 ; Sam ZUBER 1 ; Sandeep SOMAN 1 ; Ferdinand VISCO 1 , MD; Holly TOTOUOM-TANGHO 1 , MD; Hossein KALANTARI 2 , MD, MPH; Getaw Worku HASSEN 2 , MD, PhD 1 New York Medical Colleges, Metropolitan Hospital Center, Dept. of Medicine, New York, NY; 2 New York Medical Colleges, Metropolitan Hospital Center, Dept. of Emergency Medicine, New York, NY, U.S.A. Background Recognition of prolonged corrected QT (QTc) interval is of particular importance, especially when using medications known to prolong QTc interval. Methadone can prolong the QTc interval and has the potential to induce torsades de pointes. Objective The objective of this study is to investigate the accuracy of computerized ECG analysis in correctly identifying and reporting QTc inter- val in patients on methadone. Methods We conducted a retrospective review of ECGs in the Muse electronic database of patients on methadone who are above 18 years old between January 2012 and December 2013 at an urban community hospital. ECGs were analyzed by the Marquette 12SL ECG Analysis Program (GE Health- care) reviewed by a cardiologist. Results A total of 826 ECGs of patients on methadone were examined manually for the QTc interval, of which 625 (75.7%) had QTc less than 470 ms, 149 (18%) had QTc between 470-499 ms and 52 (6.3%) had QTc more than 499 ms. QTc between 470-499 ms was underestimated by machine in 19 (12.8%) ECGs and QTc more than 499 ms was underestimated in 10 (19.6%) when compared to manually calculated QTc. QTc prolongation was underreported in 63 ECGs (48.5%) of those whose QTc between 470-499 ms and in 1 ECG (2.4%) of those whose QTc was more than 499 ms. Conclusions QTc can be underestimated or unreported by the computer analysis. Physicians not only should calculate QTc manually but also examine the actual QTc value displayed on the report before concluding that this parameter is normal, especially in patients who are at risk of QTc prolon- gation. Keywords Computer-aided ECG analysis – electrocardiography – long-QT – methadone. even cardiologists 4,5 . The transition from analogue to digital ECGs resulted in automated computer analysis of the ECG (ECG-C) and is becoming a part of modern medical practice. In addition to reporting QT interval measurements and corresponding corrected QT (QTc) values, the ECG analysis software can generate a diag- nostic statement notifying the physician that a given QTc is prolonged. Many physicians remain unaware of the hazards of relying on these preliminary diagnostic inter- pretations especially in patients being considered for treatment with a known QT-prolonging drug. With an increased reliance on these readings for point-of-care decision making, clinicians must remain aware of many limitations of the ECG-C. Unfortunately, there is the possibility of computer underestimation of the QTc