Adv. Cardiol., vol. 19, pp. 185-186 (Karger, Basel 1977)
Algorithm for Computer Recognition of Infarction Localizations I. RUTIKAY-NEDECKY, V. SZATHMARY and S. CAGAN
The idea behind the algorithm for recognition of different VCG patterns of myocardial infarction was to build the decision rules exclusively on the spatial localization of instantaneous QRS vector end-points. These, in the Cartesian reference frame, are well amenable to mathematical treatment and, at the same time, they do have also definite physiological correlates in the actual spatial distribution of excitation boundaries and, at last but not least, man is able to manipulate them in a creative way in his naive visual imagination. Spatial vectorcardiograms of population groups may be expressed as time and space variable sets of instantaneous vector termini. The problem is then to find appropriate instants of QRS, when the spatial configuration of sets allows a best between- group discrimination. An index [RUTIKAYNEDECKY, 1975] was used for identification of such best-discriminative QRS vectors and plane projections, for 6 typical infarct localizations in a total of 196 patients with clinically proven past myocardial infarction, each diagnostic group consisting of not less than 30 patients. They were: the horizontal plane projection of the 10-msec vector for anteroseptal and anterolateral infarctions, the horizontal plane projection of the 20-msec vector for lateral infarctions, the sagittal plane projection of the 20-msec vector for posteroseptal infarctions, the 30-msec vector for diafragmatic infarctions, the 30- and 40-msec vector for posteroseptal infarctions. The localization of the 20-msec sagittal plane vector was found to be informative of the clockwise, or anticlockwise direction of loop inscription in the same plane of reference. The criterion if the vector end-points of a given subject in the abovementioned time instants and plane projections are members of one of the
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:58:05 AM
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences and Municipal Hospital, Bratislava
RUTIKAY-NEDECKV/SZATHMARy/CAGAN
186
typical infarction localization sets, or of sets of healthy subjects, derived from another study [RUITKAY-NEDECKY, 1973], or cannot be included into any of these sets, was incorporated into the logics of the decision tree. This served as the algorithm for a program written in Algol IV furnishing 27 possible statements in any combination: 6 basic localizations, 7 statements concerning the extent of the lesion, 13 (as regards the diagnosis of myocardial infarction) of non-specific abnormalities of the instantaneous QRS vectors, and/or the maximum T vector, and finally, a statement of error data, and a statement that the VCG pattern is normal. The recognition of non-specific QRS and T wave abnormalities may be used as a clue for implementation of this subprogram as a subroutine into wider conceived differential diagnostic programs.
References
I. RUTTKAY-NEDECKY, MD, CSc, Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, 88423 Bratislava (Czechoslovakia)
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:58:05 AM
RUTIKAY-NEDECKY, I.: Information content of instantaneous QRS vectors. Adv. Cardiol., vol. 16, pp. 52-54 (Karger, Basel 1976). RUTTKAY-NEDECKY, I.: NormaIny vektorkardiogram v axiaInom zvodovom systeme podl'a McFeeho. (Normal vectorcardiogram in the axial lead system of McFee.) Bratis. lek. Listy 59: 682-690 (1973).
Algorithm for Computer Recognition of Infarction Localizations I. RUTIKAY-NEDECKY, V. SZATHMARY and S. CAGAN
The idea behind the algorithm for recognition of different VCG patterns of myocardial infarction was to build the decision rules exclusively on the spatial localization of instantaneous QRS vector end-points. These, in the Cartesian reference frame, are well amenable to mathematical treatment and, at the same time, they do have also definite physiological correlates in the actual spatial distribution of excitation boundaries and, at last but not least, man is able to manipulate them in a creative way in his naive visual imagination. Spatial vectorcardiograms of population groups may be expressed as time and space variable sets of instantaneous vector termini. The problem is then to find appropriate instants of QRS, when the spatial configuration of sets allows a best between- group discrimination. An index [RUTIKAYNEDECKY, 1975] was used for identification of such best-discriminative QRS vectors and plane projections, for 6 typical infarct localizations in a total of 196 patients with clinically proven past myocardial infarction, each diagnostic group consisting of not less than 30 patients. They were: the horizontal plane projection of the 10-msec vector for anteroseptal and anterolateral infarctions, the horizontal plane projection of the 20-msec vector for lateral infarctions, the sagittal plane projection of the 20-msec vector for posteroseptal infarctions, the 30-msec vector for diafragmatic infarctions, the 30- and 40-msec vector for posteroseptal infarctions. The localization of the 20-msec sagittal plane vector was found to be informative of the clockwise, or anticlockwise direction of loop inscription in the same plane of reference. The criterion if the vector end-points of a given subject in the abovementioned time instants and plane projections are members of one of the
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:58:05 AM
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences and Municipal Hospital, Bratislava
RUTIKAY-NEDECKV/SZATHMARy/CAGAN
186
typical infarction localization sets, or of sets of healthy subjects, derived from another study [RUITKAY-NEDECKY, 1973], or cannot be included into any of these sets, was incorporated into the logics of the decision tree. This served as the algorithm for a program written in Algol IV furnishing 27 possible statements in any combination: 6 basic localizations, 7 statements concerning the extent of the lesion, 13 (as regards the diagnosis of myocardial infarction) of non-specific abnormalities of the instantaneous QRS vectors, and/or the maximum T vector, and finally, a statement of error data, and a statement that the VCG pattern is normal. The recognition of non-specific QRS and T wave abnormalities may be used as a clue for implementation of this subprogram as a subroutine into wider conceived differential diagnostic programs.
References
I. RUTTKAY-NEDECKY, MD, CSc, Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, 88423 Bratislava (Czechoslovakia)
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:58:05 AM
RUTIKAY-NEDECKY, I.: Information content of instantaneous QRS vectors. Adv. Cardiol., vol. 16, pp. 52-54 (Karger, Basel 1976). RUTTKAY-NEDECKY, I.: NormaIny vektorkardiogram v axiaInom zvodovom systeme podl'a McFeeho. (Normal vectorcardiogram in the axial lead system of McFee.) Bratis. lek. Listy 59: 682-690 (1973).
