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 short-term reproducibility of the signal-averaged ECG (SAECG) with three analysis techniques, conventional time-domain analysis, spectral-temporal mapping (STM), and spectral-turbulence analysis (STA), in a large series of normal subjects and patients with acute myocardial infarction (AMI). Two consecutive 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 R2 correlations, statistically fewer inconsistent diagnostic recordings, and statistically smaller differences compared with other techniques. STM was the least reproducible, justifying caution in its current form. Although STA was significantly less reproducible than time-domain analysis, it was also significantly better than STM. Two STA parameters, spectral entropy and interslice correlation mean, showed good reproducibility, suggesting that modification of this analysis technique could be useful in risk stratification.