The aim of this study was to evaluate myocardial cell damage after radiofrequency ablation (RFA), one of the most effective methods for the treatment of arrhythmias. Thirty patients aged 30.4 +/- 8.6 years were examined. Biochemical parameters were evaluated repeatedly 6-18 h after RFA. Positive troponin T (Tn-T) test and increased CK-Mb activity (p < 0.22) were observed in 8 patients (group 1), while in group II Tn-T test was negative. Biochemical findings in group I correlated with the results of ECG body surface mapping (STT) (negative area), duration and number of RFA lesions. Myocardial damage was detected using 3 cardiac markers: myo/CK-Mb and Tn-T. These testing should be carried out in due time repeatedly, in order to catch the STT maps and biochemical parameters were in high correlation after RFA. Presumably, T-wave abnormalities in Tn-T-negative group after RFA were due to the cardiac memory phenomenon. Myo/CK-Mb after RFA in Tn-T-positive group coincided with that in acute myocardial infarction. Hence, myocardial damage after RFA can be confirmed by the Tn-T test, which is helpful in the differential diagnosis of minor myocardial damage and cardiac memory phenomenon.