| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Cardiology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215
T-wave alternans is a marker of cardiac electrical instability with the potential for arrhythmia risk stratification. The modified moving average method was developed to measure alternans in settings with artifacts, noise, and nonstationary data. Algorithms were developed and performance characteristics were validated with simulated electrocardiograms (ECGs). Experimental laboratory ECGs with dynamically changing alternans values were analyzed. Alternans values estimated by modified moving average analysis correlated strongly with input alternans values (r2 = 0.9999). Rapidly changing alternans levels and phase reversals did not perturb the measurement. When heart rate was increased from 60 to 180 beats/min, with T-wave alternans apex moving from 237 to 103 ms after the R wave, the measured alternans peak varied <5% from input value. Simulated 50- to 1,000-µV motion artifact spikes typical of treadmill ECGs produced inaccuracies <2%. Alternans values in experimental laboratory study using standard electrodes tracked vulnerability to myocardial ischemia-induced ventricular fibrillation with 100% sensitivity and specificity at a cut point of 0.75 mV. Modified moving average analysis is a robust method that precisely measures T-wave alternans in settings with artifacts, noise, and nonstationary data typical of clinical ECGs and yields an accurate estimate of risk for ventricular fibrillation.
risk assessment; sudden cardiac death; ventricular arrhythmias; ambulatory electrocardiogram; exercise treadmill testing
This article has been cited by other articles:
|
|
 |
|
  M. B. Harvey and J. W. Buchanan Characterization of T Wave Alternans With Ambulatory Electrocardiography Biol Res Nurs, January 1, 2008; 9(3): 223 - 230. [Abstract] [PDF]
|
|
|
|
 |
|
 D. V. Exner, K. M. Kavanagh, M. P. Slawnych, L. B. Mitchell, D. Ramadan, S. G. Aggarwal, C. Noullett, A. Van Schaik, R. T. Mitchell, M. A. Shibata, et al. Noninvasive Risk Assessment Early After a Myocardial Infarction: The REFINE Study J. Am. Coll. Cardiol., December 11, 2007; 50(24): 2275 - 2284. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Nieminen, T. Lehtimaki, J. Viik, R. Lehtinen, K. Nikus, T. Koobi, K. Niemela, V. Turjanmaa, W. Kaiser, H. Huhtala, et al. T-wave alternans predicts mortality in a population undergoing a clinically indicated exercise test Eur. Heart J., October 1, 2007; 28(19): 2332 - 2337. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Mantravadi, B. Gabris, T. Liu, B.-R. Choi, W. C. de Groat, G. A. Ng, and G. Salama Autonomic Nerve Stimulation Reverses Ventricular Repolarization Sequence in Rabbit Hearts Circ. Res., April 13, 2007; 100(7): e72 - e80. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Shusterman, A. Goldberg, and B. London Upsurge in T-Wave Alternans and Nonalternating Repolarization Instability Precedes Spontaneous Initiation of Ventricular Tachyarrhythmias in Humans Circulation, June 27, 2006; 113(25): 2880 - 2887. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. J. Rutherford, T. H. Clutton-Brock, and M. J. Parkes Hypocapnia reduces the T wave of the electrocardiogram in normal human subjects Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2005; 289(1): R148 - R155. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. J. Kop, D. S. Krantz, B. D. Nearing, J. S. Gottdiener, J. F. Quigley, M. O'Callahan, A. A. DelNegro, T. D. Friehling, P. Karasik, S. Suchday, et al. Effects of Acute Mental Stress and Exercise on T-Wave Alternans in Patients With Implantable Cardioverter Defibrillators and Controls Circulation, April 20, 2004; 109(15): 1864 - 1869. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. M. I. Caron, L. R. James, H.-S. Kim, J. Knowles, R. Uhlir, L. Mao, J. R. Hagaman, W. Cascio, H. Rockman, and O. Smithies Cardiac hypertrophy and sudden death in mice with a genetically clamped renin transgene PNAS, March 2, 2004; 101(9): 3106 - 3111. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. D. Nearing and R. L. Verrier Tracking cardiac electrical instability by computing interlead heterogeneity of T-wave morphology J Appl Physiol, December 1, 2003; 95(6): 2265 - 2272. [Abstract] [Full Text]
|
|
|
|
|
|
K. Kumar, K. Nguyen, S. Waxman, B. D. Nearing, G. A. Wellenius, S. X. Zhao, and R. L. Verrier Potent antifibrillatory effects of intrapericardial nitroglycerin in the ischemic porcine heart J. Am. Coll. Cardiol., May 21, 2003; 41(10): 1831 - 1837. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. D. Nearing and R. L. Verrier Progressive Increases in Complexity of T-Wave Oscillations Herald Ischemia-Induced Ventricular Fibrillation Circ. Res., October 18, 2002; 91(8): 727 - 732. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
