Analysis of abnormal intra-QRS potentials. Improved predictive value for arrhythmic events with the signal-averaged electrocardiogram.

BACKGROUND Using the signal-averaged ECG (SAECG), this study developed a new electrical index for predicting arrhythmic events: abnormal intra-QRS potentials (AIQP). METHODS AND RESULTS We studied 173 patients followed after myocardial infarction for a mean duration of 14 +/- 7 months. Sixteen arrhythmic events occurred, defined as sudden cardiac death, documented sustained ventricular tachycardia, or non-fatal cardiac arrest. Noninvasive indices of arrhythmia risk were measured, including AIQP, conventional SAECG, Holter, and left ventricular ejection fraction (LVEF). Abnormal intra-QRS potentials were defined as abnormal signals occurring anywhere within the QRS period. They were estimated with a lead-specific, parametric modeling method that removed the smooth, predictable part of the QRS. AIQPs are characterized by the remaining transient, unpredictable component of the QRS and manifest as low-amplitude notches and slurs. A combined XYZ-lead AIQP index exhibited higher specificity (95%) and predictive value (PV) (+PV, 47%; -PV, 94%) than the conventional SAECG in combination with Holter and LVEF (specificity, 89%; +PV, 25%; -PV, 93%). CONCLUSIONS AIQP improved specificity and predictive value, compared with conventional tests, for prediction of arrhythmic events. AIQP emerged as the best noninvasive univariate predictor of arrhythmic events after myocardial infarction in this study. A review of several other reports shows that AIQP in the present study outperformed the conventional predictive indices reported in those other data sets.

[1]  P. Langner,et al.  The Value of High Fidelity Electrocardiography Using the Cathode Ray Oscillograph and an Expanded Time Scale , 1952, Circulation.

[2]  B E Sobel,et al.  Fast-Fourier transform analysis of signal-averaged electrocardiograms for identification of patients prone to sustained ventricular tachycardia. , 1984, Circulation.

[3]  A. Camm,et al.  High gain signal averaged electrocardiogram combined with 24 hour monitoring in patients early after myocardial infarction for bedside prediction of arrhythmic events. , 1988, British heart journal.

[4]  M Borggrefe,et al.  Relation between ventricular late endocardial activity during intraoperative endocardial mapping and low-amplitude signals within the terminal QRS complex on the signal-averaged surface electrocardiogram. , 1990, The American journal of cardiology.

[5]  J P Miller,et al.  The relationships among ventricular arrhythmias, left ventricular dysfunction, and mortality in the 2 years after myocardial infarction. , 1984, Circulation.

[6]  Mark E. Josephson,et al.  Differences in Electrophysiological Substrate in Patients With Coronary Artery Disease and Cardiac Arrest or Ventricular Tachycardia: Insights From Endocardial Mapping and Signal‐Averaged Electrocardiography , 1991, Circulation.

[7]  A. Camm,et al.  Risk stratification for arrhythmic events in postinfarction patients based on heart rate variability, ambulatory electrocardiographic variables and the signal-averaged electrocardiogram. , 1991, Journal of the American College of Cardiology.

[8]  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.

[9]  Jeffrey E. Saffitz,et al.  Reentrant and Focal Mechanisms Underlying Ventricular Tachycardia in the Human Heart , 1992, Circulation.

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

[11]  D L Jones,et al.  Time-frequency structure of the high-resolution ECG. , 1994, Journal of electrocardiology.

[12]  E. Caref,et al.  Spectral turbulence analysis of the signal-averaged electrocardiogram and its predictive accuracy for inducible sustained monomorphic ventricular tachycardia. , 1991, The American journal of cardiology.

[13]  J. Miller,et al.  Decreased heart rate variability and its association with increased mortality after acute myocardial infarction. , 1987, The American journal of cardiology.

[14]  M. Simson.  Use of Signals in the Terminal QRS Complex to Identify Patients with Ventricular Tachycardia After Myocardial Infarction , 1981, Circulation.

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

[16]  Douglas L. Jones,et al.  Analysis of abnormal signals within the QRS complex of the high-resolution electrocardiogram , 1997, IEEE Transactions on Biomedical Engineering.

[17]  J. Bigger,et al.  Importance of the endpoint of noise reduction in analysis of the signal-averaged electrocardiogram. , 1989, The American journal of cardiology.

[18]  M. Josephson,et al.  Relation of late potentials to site of origin of ventricular tachycardia associated with coronary heart disease. , 1985, The American journal of cardiology.

[19]  E J Berbari,et al.  High-resolution electrocardiography. , 1988, Critical reviews in biomedical engineering.

[20]  R E Ideker,et al.  Evaluation of a QRS Scoring System for Estimating Myocardial Infarct Size: I. Specificity and Observer Agreement , 1982, Circulation.

[21]  L. Horan,et al.  The Anatomic Basis for High‐Frequency Components in the Electrocardiogram , 1969, Circulation.

[22]  M. Josephson,et al.  Results of signal-averaged electrocardiography and electrophysiologic study in patients with nonsustained ventricular tachycardia after healing of acute myocardial infarction. , 1987, The American journal of cardiology.

[23]  S. Pogwizd,et al.  Contribution of Myocardium Responsible for Ventricular Tachycardia to Abnormalities Detected by Analysis of Signal‐Averaged ECGs , 1992, Circulation.

[24]  M. Josephson,et al.  Identification of patients with ventricular tachycardia after myocardial infarction: signal-averaged electrocardiogram, Holter monitoring, and cardiac catheterization. , 1984, Circulation.

[25]  Ralph Lazzara,et al.  Critical Analysis of the Signal‐Averaged Electrocardiogram Improved Identification of Late Potentials , 1993, Circulation.

[26]  A H Harken,et al.  Relation between late potentials on the body surface and directly recorded fragmented electrograms in patients with ventricular tachycardia. , 1983, The American journal of cardiology.

[27]  P. Langner,et al.  Further Studies in High Fidelity Electrocardiography: Myocardial Infarction , 1953, Circulation.

[28]  J. Bigger,et al.  Prevalence, characteristics and significance of ventricular tachycardia (three or more complexes) detected with ambulatory electrocardiographic recording in the late hospital phase of acute myocardial infarction. , 1981, The American journal of cardiology.

[29]  J. Fleiss,et al.  Predicting arrhythmic events after acute myocardial infarction using the signal-averaged electrocardiogram. , 1992, The American journal of cardiology.

[30]  Lennart Ljung,et al.  System Identification: Theory for the User , 1987 .

[31]  R Lazzara,et al.  An introduction to high-resolution ECG recordings of cardiac late potentials. , 1988, Archives of internal medicine.

[32]  B R Chaitman,et al.  Independent value of signal-averaged electrocardiography and left ventricular function in identifying patients with sustained ventricular tachycardia with coronary artery disease. , 1987, The American journal of cardiology.

[33]  L. Horan,et al.  Localization of the Site of Myocardial Scarring in Man by High‐Frequency Components , 1969, Circulation.

[34]  N. Sammel,et al.  Prediction of serious arrhythmic events after myocardial infarction: signal-averaged electrocardiogram, Holter monitoring and radionuclide ventriculography. , 1987, Journal of the American College of Cardiology.

[35]  G. Steinbeck,et al.  Top-resolution frequency analysis of electrocardiogram with adaptive frequency determination. Identification of late potentials in patients with coronary artery disease. , 1990, Circulation.

[36]  S L Winters,et al.  A new noninvasive index to predict sustained ventricular tachycardia and sudden death in the first year after myocardial infarction: based on signal-averaged electrocardiogram, radionuclide ejection fraction and Holter monitoring. , 1987, Journal of the American College of Cardiology.

[37]  P Lander,et al.  Principles and signal processing techniques of the high-resolution electrocardiogram. , 1992, Progress in cardiovascular diseases.