Detection of electrode interchange in precordial and orthogonal ECG leads

This study presents methods for automated detection of interchanged precordial and orthogonal ECG leads that may prevent from incorrect diagnosis and treatment. For precordial leads V1-V6, correlation coefficients of QRS-T patterns and time-alignment of R and S-peaks are assessed. For orthogonal leads (X,Y,Z), analysis of QRS loops in the frontal plane, a set of correlation coefficients and a time-alignment of leads are implemented. The methods are elaborated using 15-lead ECG databases - 77 healthy control recordings from PTB database (training), and the total set of 1220 ECGs in CSE database with various arrhythmias (test). The specificity (Sp) for detection of the correct precordial leads configuration (V1 to V6) is 93.5% (training) and 91% (test) and the mean sensitivity (Se) for 23 simulated most common chest electrode swaps is 95.7% (training) and 95% (test). Sp for detection of the correct orthogonal leads X,Y,Z is 98.7% (training) and 93.3% (test), while mean Se for 47 reversals of electrode couples A/I, F/H, M/E is 98.5%, equal for both training and test databases.