[The influence of organic myocardial damage on parameters of signal-averaged electrocardiogram in patients with electrically-induced atrial fibrillation].

The aim of this study was to assess the effects of myocardium organic damage on time-domain parameters of atrial signal-averaged ECG (ASAECG) in patients with electrically induced paroxysmal atrial fibrillation (PAF). The investigation was done in 120 patients with subjective symptoms of cardiac rhythm disorders suggesting atrial fibrillation and for further analysis were selected 51 patients in whom atrial PAF was induced during transoesophageal pacing (TEP). Patients were divided according to organic damage of myocardium-38 pts (24 male and 14 female, mean age 52.1 +/- 11.6-group I) and without-13 pts (9 male and 4 female, mean age 35.4 +/- 9.9 -group II). In all two dimensional echocardiographic examination, 24-hours Holter monitoring, exercise testing and TEP were made. Recording of ASAECG was done with a commercially available system HIPEC-200 HA Aerotel. The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10, 20, 30 ms of the filtered P-wave (RMS 10, 20, 30) and time duration of filtered P-wave (PWD) and also time duration of P-wave from Frank's leads X, Y, Z (XP, YP, ZP). Atrial late potentials (ALP) were defined as the presence of two parameters: RMS 10 < 4 microV and PWD > 123 ms. If we compared time-domain parameters of ASAECG between examined groups it occurred that only the values of PWD attained statistically significant differences, respectively 123.3 +/- 15.4 ms vs 115 +/- 11.2 ms, p < 0.05. In 14 (36.8%) patients from first group and in 2 (15.4%) patients from second ALP were confirmed. We concluded that presence of myocardium organic damage have essentially influenced on time duration of filtered P-wave.