Methods for assessment of ventricular repolarization: a model study

It is well established that non-invasive assessment of the repolarization has clinical importance in identification of ventricular arrhythmia prone state. The authors' aim was to provide a model verification of a newly developed method based on activation recovery interval (ARI) measurement. ARI is defined from the time of intrinsic deflection of the QRS (time of minimum dV/dT) to the time of maximum upstroke velocity near the peak of the T wave (time of maximum dV/dT). ARI showed higher spatial sensitivity on the epicardial surface than QT interval (QTI) but difficulties have been arisen when body surface (BS) interpretation occurred. The accomplished model study reinforces the utility of the theoretically based estimation but proves that the direct BS applicability is limited in consequence of the filtering effect of the torso. On BS level ARI can be interpreted with statistical tools (first and second moments). The magnitude curve as a suitable feature extraction provides a tool for detection of pathological disparity of the repolarization process.