SHORT-TERM REPRODUCIBILITY OF TIME-DOMAIN, SPECTRAL TEMPORAL MAPPING,AND SPECTRAL TURBULENCE ANALYSIS OF THE SIGNAL-AVERAGED ELECTROCARDIOGRAM IN NORMAL SUBJECTS AND PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

The aim of this prospective study was to compare the shortterm reprodu cibility of the signal-averaged ECG (SAECG) with three analysis techni ques, conventional time-domain analysis, spectral-temporal mapping (ST M), and spectral-turbulence analysis (STA), in a large series of norma l subjects and patients with acute myocardial infarction (AMI). Two co nsecutive SAECGs were recorded in 225 consecutive patients 10.2 +/- 2. 7 days after AMI and in 85 healthy volunteers. The visual, diagnostic, and quantitative reproducibility of the three techniques was compared . Time-domain analysis was the most reproducible method, having high R (2) correlations, statistically fewer inconsistent diagnostic recordin gs, and statistically smaller differences compared with other techniqu es. STM was the least reproducible, justifying caution in its current form. Although STA was significantly less reproducible than time-domai n analysis, it was also significantly better than STM. Two STA paramet ers, spectral entropy and interslice correlation mean, showed good rep roducibility, suggesting that modification of this analysis technique could be useful in risk stratification.