[A study on effective parameters to represent the heterogeneity in ventricular repolarization].
The aim of this study was to investigate whether ARI (activation-recovery interval) dispersion on the sheep epicardium was related with the ischemia induced heterogeneity in ventricular repolarization. We have developed an algorithm based on wavelet transformation to analyze ARI from a 64-channel epicardial ECG data of an ischemic sheep. The quadratic spline wavelet was used to extract QRS with 2(1) scale and T wave with 2(5) scale, and then A and R points were determined by definition. It was found that there was not a significant difference in the average ARI on the epicardium before and during ischemia. Meanwhile ARI dispersion on the epicardium was significantly increased during ischemia (126.3 ms vs 59.9 ms, P = 0.0007). Furthermore, a computer simulation showed that ARI is very close to ADP, suggesting that ARI dispersion may be an effective parameter to estimate the heterogeneity in ventricular repolarization induced by ischemia.