Q: What are the normal QTc intervals in hospitalized patients?
According to a scientific statement from the American College of Cardiology (ACC) and the Heart Rhythm Society (HRS), the normal value for QTc in general population is:
below 450ms for men and
below 460ms for women
But in a recent ACC consensus document an expert writing group suggest that in a hospital setting the upper limit be raised to the 99th percentile of normal:
470ms in males and
480 ms in females
(In any case, QTc more than 500ms is considered highly abnormal).
1. Rautaharju PM, Surawicz B, Gettes LS, Bailey JJ, Childers R, Deal BJ, Gorgels A, Hancock EW, Josephson M, Kligfield P, Kors JA, Macfarlane P, Mason JW, Mirvis DM, Okin P, Pahlm O, van Herpen G, Wagner GS, and Wellens H. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part IV: the ST segment, T and U waves, and the QT interval: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology. Circulation 2009 Mar 17; 119(10) e241-50.
Drew BJ, Ackerman MJ, Funk M, Gibler WB, Kligfield P, Menon V, Philippides GJ, Roden DM, and Zareba W. Prevention of torsade de pointes in hospital settings: a scientific statement from the American Heart Association and the American College of Cardiology Foundation. J Am Coll Cardiol 2010 Mar 2; 55(9) 934-47.