Arrhythmias, Electrophysiology and Electrocardiography
Which Lead for Q-T Interval Measurements?Davey P.P.
Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
Do you have an account?
- Rent for 48h to view
- Buy Cloud Access for unlimited viewing via different devices
- Synchronizing in the ReadCube Cloud
- Printing and saving restrictions apply
Rental: USD 8.50
Cloud: USD 20.00
There are several Q-T interval measures (individual lead, mean Q-T interval or Q-T dispersion) from a 12-lead ECG. Which should be used? As the ECG provides twelve different measures of the heart’s ‘true’ Q-T interval, and as, ‘a priori’, no one measure is any better or worse than any other measure at estimating the ‘true’ Q-T interval, the best measure is the average of these twelve measures, i.e., the mean Q-T interval. The best single lead to measure the Q-T interval is the lead that relates most closely to the mean Q-T interval which in 49 subjects with cardiac diseases was lead V3, then lead II. The longest lead Q-T interval relates poorly to the mean and to the individual lead Q-T intervals and therefore carried information different to and quite unique from these measures. This unique information is Q-T dispersion which relates well to the longest lead Q-T interval (r = 0.71, p < 0.001).
© 2001 S. Karger AG, Basel
- Fei L, Goldman JH, Prasad K, Keeling PJ, Reardon K, Camm AJ, McKenna WJ: Q-T dispersion and RR variations on 12-lead ECGs in patients with congestive heart failure secondary to idiopathic dilated cardiomyopathy. Eur Heart J 1996;17:258–263.
- Barr CS, Naas A, Freeman M, Lang CC, Struthers AD: Q-T dispersion and sudden unexpected death in chronic heart failure. Lancet 1994;343:327–329.
- Tomaselli GF, Beuckelmann DJ, Calkins HG, Berger RD, Kessler PD, Lawrence JH, Kass D, Feldman AM, Marban E: Sudden cardiac death in heart failure: The role of abnormal repolarization. Circulation 1994;90:2534–2539.
January CT, Makielski JC: Triggered arrhythmias: New insights into basic mechanisms. Curr Opin Cardiol 1990;5:65–68.
- Munger RG, Prineas RJ, Crow RS, Changbumrung S, Keane V, Wangsuphachart V, Jones MP: Prolonged Q-T interval and risk of sudden death in South-East Asian men. Lancet 1991;338:280–281.
- Davey P: Q-T interval and mortality from coronary artery disease. Prog Cardiovasc Dis 2000;42:359–384.
- Glancy JM, Garratt CJ, Woods KL, De Bono DP: Q-T dispersion and mortality after myocardial infarction. Lancet 1995;345:945–948.
- Taylor GJ, Crampton RS, Gibson RS, Stebbins PT, Waldman MT, Beller GA: Prolonged Q-T interval at onset of acute myocardial infaction in predicting early phase ventricular tachycardia. Am Heart J 1981;102:16–24.
Ahnve S: Q-T interval prolongation in acute myocardial infarction. Eur Heart J 1985;6(suppl D):85–95.
- Juul-Moller S: Corrected Q-T-interval during one year follow-up after an acute myocardial infarction. Eur Heart J 1986;7:299–304.
- Ahnve S, Lundman T: Q-Tc intervals at discharge after acute myocardial infaction and long-term prognosis. Acta Med Scand 1980;208:55–60.
- Day CP, James OF, Butler TJ, Campbell RW: Q-T prolongation and sudden cardiac death in patients with alcoholic liver disease. Lancet 1993;341:1423–1428.
Article / Publication Details
Copyright / Drug Dosage / DisclaimerCopyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.