The Relationship between QT Dispersion and Ischemic Injuries in Myocardial Isotope Scan

  • Mohammad Assadpour Piranfar Mail Department of Cardiology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Myocardial ischemia, QT dispersion, SPECT, Isotope scan


The relationship between QT dispersion and myocardial ischemia is still controversial. Therefore, we aimed to investigate the relationship between QTd and the severity and extent of myocardial ischemia. In this cross-sectional study, 141 patients having symptoms of CAD who referred to our medical center during 2009-2010, and were examined with myocardial isotope scan and ECG, were enrolled. Based on the Electrocardiography and Single-Photon Emission Computed Tomography results, the patients were categorized as having normal, mild, moderate, and severe ischemia. QTd was measured at rest and under stress as the maximum difference between QT intervals in 12-lead ECG. Ultimately, the correlation between rest and stress QTd and the severity and extent of ischemia (number of ischemic segments and summed ischemic score) were investigated, and the rest and stress QTd was compared between the groups. QTd under stress was positively correlated with the number of ischemic segments and summed ischemic scores in all patients. In normal patients, stress and rest QTd were the same. The QTd under stress significantly increased in patients with ischemia. There was no significant difference between the groups regarding QTd at rest. Stress QTd was significantly greater in patients with severe ischemia and greater in patients with mild and moderate ischemia compared with the normal patients. Stress QTd difference between mild and moderate ischemic groups was not significant. QTd under stress is related to the severity and extent of myocardial ischemia and is clinically useful for identifying ischemic myocardial injuries.


Almeda FQ, Kason TT, Nathan S, et al. Silent Myocardial Ischemia: Concepts and controversies. Am J Med 2004;116(2):112-8.

Cardiovascular disease. WHO (Accessed in Feb 18, 2014, at cardiovascular_diseases/en/).

Greenwood JP, Maredia N, Younger JF, et al. Cardiovascular magnetic resonance and single-photon emission computed tomography for diagnosis of coronary heart disease (CE-MARC): a prospective trial. Lancet 2012;379(9814):453-60.

Masaki N, Takase B, Matsui T, et al. QT peak dispersion, not QT dispersion, is a more useful diagnostic marker for detecting exercise-induced myocardial ischemia. Heart Rhythm 2006;3(4):424-32.

Takase B, Masaki N, Hattori H, et al. Usefulness of automatic QT dispersion measurement for detecting exercise-induced myocardial ischemia. Anadolu Kardiyol Derg 2009;9(3):189-95.

Myocardial perfusion scintigraphy for the diagnosis and management of angina and myocardial infarction. National Institute for Health and Clinical Excellence (Accessed in Feb 14, 2014, at nicemedia/pdf/TA073guidance.pdf).

Mowatt G, Vale L, Perez J, et al. Systematic review of the effectiveness and cost-effectiveness, and economic evaluation, of home versus hospital or satellite unit haemodialysis for people with end-stage renal failure. Health Technol Assess 2003;7(2):1-174.

Shaw LJ, Bairey Merz CN, Pepine CJ, et al. Insights from the NHLBI-Sponsored Women's Ischemia SyndromeEvaluation (WISE) Study: Part I: gender differences in traditional and novel risk factors, symptom evaluation, and gender-optimized diagnostic strategies. J Am Coll Cardiol 2006;47(3 Suppl):S4-S20.

Goldschlager N, Selzer A, Cohn K. Treadmill stress tests as indicators of presence and severity of coronary artery disease. Ann Intern Med 1976;85(3):277-86.

Miranda CP, Liu J, Kadar A, et al. Usefulness of exerciseinduced ST-segment depression in the inferior leads during exercise testing as a marker for coronary artery disease. Am J Cardiol 1992;69(4):303-7.

Wu SC, Secchi MB, Radice M, et al. Sex differences in the prevalence of ischemic heart disease and in the response to a stress test in a working population. Eur Heart J 1981;2(6):461-5.

Ellestad MH, Savitz S, Bergdall D, et al. The false positive stress test. Multivariate analysis of 215 subjects with hemodynamic, angiographic and clinical data. Am J Cardiol 1977;40(5):681-5.

Barr CS, Naas A, Freeman M, et al. QT dispersion and sudden unexpected death in chronic heart failure. Lancet 1994;343(8893):327-9.

Lee KW, Kligfield P, Dower GE, et al. QT dispersion, T wave projection and heterogeneity of repolarization in patients with coronary artery disease. Am J Cardiol 2001;87(2):148-51.

Day CP, McComb JM, Campbell RW. QT dispersion: an indication of arrhythmia risk in patients with long QT interval. Br Heart J 1990;63(6):342-4.

Khosropanah Sh, Barkat M. The Acute Effect of Cigarette Smoking on QT Dispersion. IJMS 2002;27(2):56-9.

Linker NJ, Colonna P, Kekwick CA, et al. Assessment of QT dispersion in symptomatic patients with congenital long QT syndromes. Am J Cardiol 1992;69(6):634-8.

Glancy JM, Garratt CJ, Woods KL, et al. QT dispersion and mortality after myocardial infarction. Lancet 1995;345(8955):945-8.

Miorelli M, Buja G, Melacini P, et al. QT-interval variability in hypertrophic cardiomyopathy patients with cardiac arrest. Int J Cardiol 1994;45(2):121-7.

Pinsky DJ, Sciacca RR, Steinberg JS. QT dispersion as a marker of risk in patients awaiting heart transplantation. J Am Coll Cardiol 1997;29(7):1576-84.

Schmidt M, Schneider C, Theissen P, et al. QT dispersion in comparison to Tl-201-SPECT for detection of myocardial ischaemia. Int J Cardiol 2006;113(3):327-31.

Lazar J, Busch D, Wirkowski E, et al. Changes in QT dispersion after thrombolysis for stroke. Int J Cardiol 2008;125(2):258-62.

Jain H, Avasthi R. Correlation between dispersion of repolarization (QT dispersion) and ventricular ectopic beat frequency in patients with acute myocardial infarction: a marker for risk of arrhythmogenesis? Int J Cardiol 2004;93(1):69-73.

Haseroth K, Seyffart K, Wehling M, et al. Effects of progestin-estrogen replacement therapy on QT-dispersion in postmenopausal women. Int J Cardiol 2000;75(2-3):161-5.

Chauhan VS, Tang AS. Dynamic changes of QT interval and QT dispersion in non-Q-wave and Q-wave myocardial infarction. J Electrocardiol 2001;34(2):109-17.

Christensen PK, Gall MA, Major-Pedersen A, et al. QTc interval length and QT dispersion as predictors of mortality in patients with non-insulin-dependent diabetes. Scand J Clin Lab Invest 2000;60(4):323-32.

Nakamura T, Chin K, Hosokawa R, et al. Corrected QT dispersion and cardiac sympathetic function in patients with obstructive sleep apnea-hypopnea syndrome. Chest= 2004;125(6):2107-14.

van de Loo A, Arendts W, Hohnloser SH. Variability of QT dispersion measurements in the surface electrocardiogram in patients with acute myocardial infarction and in normal subjects. Am J Cardiol 1994;74(11):1113-8.

Moreno FL, Villanueva T, Karagounis LA, et al. Reduction in QT interval dispersion by successful thrombolytic therapy in acute myocardial infarction. TEAM-2 Study Investigators. Circulation 1994;90(1):94-100.

Perkiomaki JS, Koistinen MJ, Yli Mayry S, et al.Dispersion of QT interval in patients with and without susceptibility to ventricular tachyarrhythmias after previous myocardial infarction. J Am Coll Cardiol 1995;26(1):174 -9.

Higham PD, Furniss SS, Campbell RW. QT dispersion and components of the QT interval in ischaemia and infarction. Br Heart J 1995;73(1):32-6.

Sporton SC, Taggart P, Sutton PM, et al. Acute ischaemia: a dynamic influence on QT dispersion. Lancet 1997;349(9048):306-9.

Musha H, Kunishima T, Awaya T, et al. Influence of exercise on QT dispersion in ischemic heart disease. Jpn Heart J 1997;38(2):219-26.

Stoletniy LN, Pai RG. Value of QT dispersion in the interpretation of exercise stress test in women. Circulation 1997;96(3):904-10.

Cin VG, Celik M, Ulucan S. QT dispersion ratio in patients with unstable angina pectoris (a new risk factor?). Clin Cardiol 1997;20(6):533-5.

Schneider CA, Voth E, Baer FM, et al. QT dispersion is determined by the extent of viable myocardium in patients with chronic Q-wave myocardial infarction. Circulation 1997;96(11):3913-20.

Teragawa H, Hirao H, Muraoka Y, et al. Relation between QT dispersion and adenosine triphosphate stress thallium- 201 single-photon emission computed tomographic imaging for detecting myocardial ischemia and scar. Am J Cardiol 1999;83(8):1152-6.

Al Mohammad A, Mahy IR, Buckley A, et al. Does the presence of hibernating myocardium in patients with impaired left ventricular contraction affect QT dispersion? Am Heart J 2001;141(6):944-8.

Hachamovitch R, Berman DS, Kiat H, et al. Exercise myocardial perfusion SPECT in patients without known coronary artery disease: incremental prognostic value and use in risk stratification. Circulation 1996;93(5):905-14.

Savelieva I, Yap YG, Yi G, et al. Comparative reproducibility of QT, QT peak, and T peak-T end intervals and dispersion in normal subjects, patients with myocardial infarction, and patients with hypertrophic cardiomyopathy. Pacing Clin Electrophysiol 1998;21(11 Pt2):2376-81.

Malik M, Acar B, Gang Y, et al. QT dispersion does not represent electrocardiographic interlead heterogeneity of ventricular repolarization. J Cardiovasc Electrophysiol 2000;11(8):835-43.

Okin PM, Devereux RB, Howard BV, et al. Assessment of QT interval and QT dispersion for prediction of all-cause and cardiovascular mortality in American Indians: The Strong Heart Study. Circulation 2000;101(1):61-6.

Stierle U, Giannitsis E, Sheikhzadeh A, et al. Relation between QT dispersion and the extent of myocardial ischemia in patients with three-vessel coronary artery disease. Am J Cardiol 1998;81(5):564-8.

Koide Y, Yotsukura M, Yoshino H, et al. Value of QT dispersion in the interpretation of treadmill exercise electrocardiograms of patients without exercise-induced chest pain or ST-segment depression. Am J Cardiol2000;85(9):1094-9.

Koide Y, Yotsukura M, Yoshino H, et al. Usefulness ofQT dispersion immediately after exercise as an indicator of coronary stenosis independent of gender or exerciseinduced ST-segment depression. Am J Cardiol 2000;86(12):1312-7.

Arab D, Valeti V, Schunemann HJ, López-Candales A. Usefulness of the QTc interval in predicting myocardial ischaemia in patients undergoing exercise stress testing. Am J Cardiol 2000;85(6):764-6.

Carluccio E, Biagioli P, Bentivoglio M, et al. Effects of acute myocardial ischemia on QT dispersion by dipyridamole stress echocardiography. Am J Cardiol 2003;91(4):385-90.

Coronel R, Opthof T, Taggart P, et al. Differential electrophysiology of repolarization: from clone to clinic. Cardiovasc Res 1997;33(3):503-17.

How to Cite
Piranfar MA. The Relationship between QT Dispersion and Ischemic Injuries in Myocardial Isotope Scan. Acta Med Iran. 52(5):345-351.