Quantifying QRS changes during myocardial ischemia: Insights from high frequency electrocardiography.

Over four decades of high frequency electrocardiography research have provided a body of knowledge about QRS changes during myocardial ischemia, and the techniques to measure and quantify them. High-frequency QRS (HFQRS) components, being closely related to the pattern of ventricular depolarization, carry valuable clinical information. Changes in HFQRS amplitude and morphology have been shown to be sensitive diagnostic markers of myocardial ischemia, often superior to measures of ST-T segment changes. Clinical studies in patients undergoing exercise testing have consistently demonstrated the incremental diagnostic value of HFQRS analysis in detection of demand ischemia. In 6 studies that evaluated the HyperQ™ technology, the average sensitivity and specificity of HFQRS analysis were 75%±6% and 80%±6%, respectively, compared to average sensitivity 48%±16% and average specificity 70%±15% of ST segment analysis. In patients with acute supply ischemia, recent studies characterized and quantified the ischemic HFQRS patterns. HFQRS morphology index was found to be higher in patients with acute coronary syndrome (ACS), compared to non-ischemic, with good sensitivity in patients without ST elevation. These research findings may be translated into commercially-available ECG systems and be used in clinical practice for improved diagnosis and monitoring of myocardial ischemia.

[1]  H. Huikuri,et al.  Association of Early Repolarization and Sudden Cardiac Death During an Acute Coronary Event , 2012, Circulation: Arrhythmia and Electrophysiology.

[2]  E. Toledo,et al.  Ischemia monitoring by analysis of depolarization changes , 2008, 2008 Computers in Cardiology.

[3]  Eran Toledo,et al.  Use of electrocardiographic depolarization abnormalities for detection of stress-induced ischemia as defined by myocardial perfusion imaging. , 2012, The American journal of cardiology.

[4]  Alan H Feiveson,et al.  Real-time 12-lead high-frequency QRS electrocardiography for enhanced detection of myocardial ischemia and coronary artery disease. , 2004, Mayo Clinic proceedings.

[5]  Daniel E Forman,et al.  Exercise standards for testing and training: a scientific statement from the American Heart Association. , 2013, Circulation.

[6]  D. Geselowitz,et al.  High-frequency components in the electrocardiograms of normal subjects and of patients with coronary heart disease. , 1961, American heart journal.

[7]  Olle Pahlm,et al.  Comparison of high-frequency QRS components and ST-segment elevation to detect and quantify acute myocardial ischemia. , 2010, Journal of electrocardiology.

[8]  S. Akselrod,et al.  Effects of coronary occlusion on high-frequency content of the epicardial electrogram and body surface electrocardiogram. , 1987, Circulation.

[9]  S. Abboud,et al.  Detection of stress-induced myocardial ischemia from the depolarization phase of the cardiac cycle--a preliminary study. , 2009, Journal of electrocardiology.

[10]  E. W. Hancock,et al.  Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Card , 2007, Journal of the American College of Cardiology.

[11]  Jin-oh Choi,et al.  Improved Detection of Ischemic Heart Disease by Combining High-Frequency Electrocardiogram Analysis with Exercise Stress Echocardiography , 2013, Korean circulation journal.

[12]  G. Amit,et al.  High-frequency QRS analysis improves the specificity of exercise ECG testing in women referred for angiography. , 2013, Journal of electrocardiology.

[13]  Guy Amit,et al.  The cost-effectiveness of stress testing using high-frequency QRS analysis , 2013, Int. J. Medical Eng. Informatics.

[14]  O Pahlm,et al.  Changes in high-frequency QRS components are more sensitive than ST-segment deviation for detecting acute coronary artery occlusion. , 2000, Journal of the American College of Cardiology.

[15]  Pablo Laguna,et al.  Detection and quantification of acute myocardial ischemia by morphologic evaluation of QRS changes by an angle-based method. , 2013, Journal of electrocardiology.

[16]  M. Yamaki,et al.  Decrease in the high frequency QRS components depending on the local conduction delay. , 1998, Japanese circulation journal.

[17]  S Abboud.  Subtle alterations in the high-frequency QRS potentials during myocardial ischemia in dogs. , 1987, Computers and biomedical research, an international journal.

[18]  L. Piegas,et al.  Initial clinical results using intracardiac electrogram monitoring to detect and alert patients during coronary plaque rupture and ischemia. , 2010, Journal of the American College of Cardiology.

[19]  A L Goldberger,et al.  Effect of Myocardial Infarction on High‐frequency QRS Potentials , 1981, Circulation.

[20]  E. W. Hancock,et al.  Recommendations for the standardization and interpretation of the electrocardiogram: part II: Electrocardiography diagnostic statement list: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College , 2007, Circulation.

[21]  Elin Trägårdh,et al.  Reduced high-frequency QRS components in patients with ischemic heart disease compared to normal subjects. , 2004, Journal of electrocardiology.

[22]  R J Cohen,et al.  Detection of transient myocardial ischemia by computer analysis of standard and signal-averaged high-frequency electrocardiograms in patients undergoing percutaneous transluminal coronary angioplasty. , 1987, Circulation.

[23]  J. P. C. de Weerd,et al.  Accuracy of QRS detection in relation to the analysis of high-frequency components in the electrocardiogram , 1979, Medical and Biological Engineering and Computing.

[24]  S. Abbound,et al.  High frequency ECG during reperfusion therapy of acute myocardial infarction , 1990, [1990] Proceedings Computers in Cardiology.

[25]  O Pahlm,et al.  The absence of high-frequency QRS changes in the presence of standard electrocardiographic QRS changes of old myocardial infarction. , 2001, American heart journal.

[26]  M. Gulati,et al.  Exercise in Cardiovascular Disease Exercise Stress Testing in Women Going Back to the Basics , 2010 .

[27]  Pavel Jurák,et al.  Ultra-high-frequency ECG measurement , 2013, Computing in Cardiology 2013.

[28]  S. Abboud,et al.  High‐Frequency QRS Analysis in Patients with Acute Myocardial Infarction: A Preliminary Study , 2013, Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc.

[29]  S Abboud,et al.  High frequency electrocardiography using an advanced method of signal averaging for non-invasive detection of coronary artery disease in patients with normal conventional electrocardiogram. , 1986, Journal of electrocardiology.

[30]  E. Antman,et al.  ACC/AHA 2002 guideline update for exercise testing: summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines). , 2002, Journal of the American College of Cardiology.

[31]  Pablo Laguna,et al.  QRS Slopes for Detection and Characterization of Myocardial Ischemia , 2008, IEEE Transactions on Biomedical Engineering.

[32]  R J Cohen,et al.  High Frequency Electrocardiography of Three Orthogonal Leads in Dogs During a Coronary Artery Occlusion , 1989, Pacing and clinical electrophysiology : PACE.

[33]  Thomas Lavergne,et al.  Sudden cardiac arrest associated with early repolarization. , 2008, The New England journal of medicine.

[34]  Peter W Macfarlane,et al.  ECG measurements in end QRS notching and slurring. , 2013, Journal of electrocardiology.

[35]  S. Abboud,et al.  Simulation of high-resolution QRS complex using a ventricular model with a fractal conduction system. Effects of ischemia on high-frequency QRS potentials. , 1991, Circulation research.