Time-frequency analysis of ECG for late potentials in sudden cardiac death survivors and post-myocardial infarction patients.
Late potentials (LPs) are harbingers of sudden cardiac death (SCD) for certain patient populations, including SCD survivors and patients post myocardial infarction. This retrospective study examined the sensitivity and specificity of time-frequency distributions (TFDs) in detecting late potentials in 90 patients using time-domain signal average ECG criteria as a standard for comparison. Three time-domain criteria were employed: QRS duration > 114 msec; LAS > 30 msec; and RMS40 < 20 microV. Time domain criteria were compared with TFD results derived using the binomial transform. TFDs were considered positive if small magnitude (-30 dB) signals > 40 Hz were present 114 msec after the onset of the QRS complex. Results from the binomial transform are comparable to those from the SAECG method (sensitivity = 92.0-100%, specificity = 78-92%).
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T M
TM
Cardiology Service, MCHE-MDC, Brooke Army Medical Center, Ft. Sam Houston, TX 78234-6262, USA.
Rubal
B J
BJ
Bulgrin
J R
JR
Gilman
J K
JK
D000328:Adult; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors