Comparison Between Spectarl Turbulence Analysis and Late Potential Analysis of Signal-Averaged ECG in Anterior and Inferior Myocardial Infarction

Patients with inferior (I) myocardial infarction (MI) more frequently have Iate potentials (LP) than those with anterior (A) MI, since LP in the signal-averaged (SA) ECG may not be detected if abnormal ventricular regions are activated early during the QRS as in AMI. It was postulated that abnormal ventricular regions that are substrate for reentrant ventricular tachycardia cause transient changes in the velocity of the depolarization wave front resulting in increased spectral turbulence within the QRS. We compared spectral turbulence analysis (spectral turbulence ? 10 in any of the three X,Y,Z leands) with LP analysis (RMS<25 uV at 25 HZ+RMS<16 uV at 40 Hz) of the SAECG recorded in 84 pts with AMI and 86 pts with IMI. The incidence of LP was 17 % in AMI and 30% in IMI while abnormal STA occurred in 42 % of AMI and 21 % of IMI. The two techniques were concordant in 86 % of IMI but in only 68 % of AMI (p