Analysis of QRS loop changes in the beat-to-beat Vectocardiogram of ischemic patients undergoing PTCA

Abstract

In the present work, we have studied dynamic changes of QRS loop in the Vectocardiogram (VCG) of 80 patients that underwent Percutaneous Transluminal Coronary Angioplasty (PTCA). The VCG was obtained for each patient using the XYZ orthogonal leads of their electrocardiographic (ECG) records acquired before, during and after PTCA procedure. In order to analyze the variations of VCG, it has been proposed in this study the following parameters a) Maximum module of the cardiac depolarization vector, b) Volume, c) and Area of vectocardiographic loop corresponding to the QRS complex of each beat, d) Maximum distance between Centroid and the Loop, e) Angle between the XY plane and the Optimum Plane, f) Relation between the Area and Perimeter. The results obtained indicate that the parameters proposed show significant statistics differences (p-value<0.05) before, during (with some exceptions at the first minute of balloon inflation) and after PTCA. We conclude that the variations observed in the proposed parameters correctly represent not only the morphological changes in the depolarization VCG but also they reflect the modifications in the levels of cardiac ischemia induced by PTCA.

Methods for derivation of orthogonal leads from 12-lead electrocardiogram: A review

“…There is a group of interesting morphological indications obtained from VCG loops which provide a demonstrable diagnostic value. These features are provided in [59,60]. Only some are used today to compare the quality of transformations.…”

Advanced Bioelectrical Signal Processing Methods: Past, Present and Future Approach—Part I: Cardiac Signals

“…In 2006, Guillem et al [ 120 ] pre-processed signals with the implementation of the type II Chebyshev filter with a cut-off frequency equal to 1 Hz and with the Butterworth low-pass filter with a cut-off frequency of 50 Hz. Correa et al in 2009 [ 121 ] used the 8th order Butterworth low-pass filter with a cut-off frequency equal to 100 Hz and the 4th order Butterworth notch filter with a cut-off frequency equal to 60 Hz for signal processing purposes. Later, in their other publications, Correa et al, in 2013 [ 112 , 122 ], used the 4th order Butterworth band-pass filter with cut-off frequencies at and 100 Hz and the 2nd order Butterworth notch filter with a cut-off frequency equal to Hz for the purpose of signal processing.…”

Novel set of vectorcardiographic parameters for the identification of ischemic patients

“…Our hypothesis was that the morphological QRS-loop changes due to myocardial ischemia should contribute to, or even perhaps improve, the identification of such patients. A preliminary study produced promising evidence [12].…”