Evaluation of ischemic injury of the cardiac tissue by using the principal component analysis of an epicardial electrogram

Detection and evaluation of ventricular repolarization alternans: An approach to combined ECG, thoracic impedance, and beat-to-beat heart rate variability analysis

“…1. Specific brake-point in PR criteria values, according to our experience described in [27] suggested considering of first five principal components, representing more than 90% of variation in S-T,T complexes and more than 85% of variation in dZ/ dt cardiocycles, as minimal yet sufficient set of principal components for truncated expansion of the signals. Coefficients of these 5 principal components to be used for optimal representation of shape of every S-T,T complex or dZ/dt cardiocycle were considered as quantitative estimates of their shape.…”

“…Final determination of number was done according to our experience; the detail description is given in [27].…”

Efficiency Evaluation of Autonomic Heart Control by Using the Principal Component Analysis of ECG P-Wave

“…Unfortunately, a strict selection of the number of principal components to be included in truncated expansion remains problematic. As described previously [24], the number was determined at which the specific non-smooth point was visually observed in the dependency of criterion PR (ǠFormula 6). The number of principal components corresponded to the number of weight coefficients w of the basis functions in graphs in which visual correlation with the changes in the heart rhythm evoked by the orthostatic test was observed.…”

Methods for monitoring and prognosis of clinical status of patients in acute phase of myocardial infarction for computer network based clinical decision support system

“…According to our earlier experience described in [18], the number was determined at which the specific non-smooth point was visually observed in the dependency of criterion PR (formula (5)). …”