Reproducibility of signal averaged ECG analysis by spectral turbulence analysis

Spectral turbulence analysis (STA) is a new technique that evaluates the changes in wavefront velocity of the entire QRS complex of the signal-averaged ECG (SAECG). STA is applied to a region of interest of SAECG that begins 25 msec before the QRS onset (T1) and terminates 125 msec after the QRS offset (T2). This study investigates the reproducibility of the STA in 20 patients with prior myocardial infarction. STA was calculated by method described by Kelen et al. (1991), changing T1 and T2 from -10 msec to +10 msec., respectively. Results: among the four considered parameters, only interslice correlation standard deviation did not show reproducibility. Conclusion: STA resulted in high reproducibility over a wide span of region of interest, the determination of QRS onset and offset not appearing crucial in three of four parameters analyzed by STA of the SAECG