SIGNAL-AVERAGED ELECTROCARDIOGRAM AND VEN TRICULAR LATE POTENTIALS INPATIENTS WITH UNSTABLE AND STABLE ANGINA - EFFECT OF CHEMOTHERAPY

Signal-averaged electrocardiogram (ART system) was obtained in 60 pati ents with unstable angina admitted to coronary care unit (group 1) and in 48 patients with stable effort angina (group 2) on the day of admi ssion and before discharge. 22 and 24 patients had previous Q-wave and 17 and 4 patients - non-Q-wave myocardial infarction in groups 1 and 2, respectively. Ventricular late potentials were considered to be pre sent if at least two of the following criteria were met: filtered QRS duration (QRSD)>114 ms, low amplitude signals duration of the terminal QRS (LAS40)> 38 ms and root mean square voltage (RMS40)<20 mu V. Clin ical improvement was achieved in all patients. In group 1 stabilizatio n was associated with significant decrease of QRSD (p<0,02) and LAS40 (p<0,03) and insignificant increase of RMS40. VLP incidence was 47% at baseline and 35% after stabilization (p=0,26). Decline in VLP inciden ce was more pronounced in patients without previous myocardial infarct ion (from 62 to 38%) and with non-a-wave myocardial infarction (from 5 3 to 29%) compared to patients with previous myocardial infarction. Th ere were no changes in parameters of signal-averaged electrocardiogram and in incidence of VLPs (31% on admission and 25% before discharge) in 48 patients with stable effort angina. Thus stabilization of unstab le angina was associated with significant Improvement of parameters of signal-averaged electrocardiogram and VLPs reduction (most pronounced in patients without previous Q-wave myocardial infarction).