The time course and relation of positive signal-averaged electrocardiograms by time-domain and spectral temporal mapping analyses after infarction.
We evaluated the time course of development of positive signal-averaged electrocardiograms (SA-ECGs) by time-domain and Spectral Temporal Mapping (STM) analyses after myocardial infarction in 88 patients without bundle branch block. The incidence of positive SA-ECGs by time-domain analysis peaked at 4 to 8 weeks postinfarction whereas the peak incidence by STM analysis varied from 4 days to 4 to 10 months postinfarction. Positive time-domain SA-ECGs demonstrated a significantly reduced factor of normality (NF) compared with negative time-domain SA-ECGs by X, Z, or vector STM analyses, but marked overlap was present for the standard deviations of positive and negative SA-ECGs in all STM leads. Chi square analysis demonstrated a significant correlation only between X-lead STM analysis and time-domain analysis; however, the two methods were markedly discordant. Although there is a statistically significant relation between time-domain and STM analyses of SA-ECGs, the two analyses are not clinically interchangeable.
Cardiology Division, University of Texas Health Science Center at San Antonio.
M A
MA
Graceffo
R A
RA
O'Rourke
C
C
Hibner
A J
AJ
Boulet
D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D016009:Chi-Square Distribution; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D004566:Electrodes; D005069:Evaluation Studies as Topic; D005583:Fourier Analysis; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013997:Time Factors