Automated QRST subtraction algorithm for analysis of T wave obscured ectopic atrial beats

An automatic QRST subtraction algorithm to isolate ectopic P waves from the superimposed TU wave in the surface ECG was developed. QRST removal was accomplished using an adaptive template constructed from averaged QRST complexes. Sixty-two-lead body surface integral maps of obscured and nonobscured paced P waves were computed and visually and mathematically compared using correlation coefficients.