The departure index area of departure maps before and after the PTCA procedure was evaluated in 10 randomly chosen patients with clinically significant ischaemic heart disease. The body surface mapping system CARDIAG 128.1, (ZPA Prague-Cakovice) was used. The departure index was calculated using Kubota's formula. The departure indexes of the ST-T interval and departure maps of 36 ms and 80 ms intervals from the J point were followed. A decrease of the departure index area was considered as a sign of successful PTCA. A correct classification was made in 6 patients out of 9 (66%) with successfully performed PTCA. The identification of one patient with unsuccessful PTCA procedure was also correctly determined. The overall correlation between the effect of PTCA and the departure index area change was 7 out of 10 (70%). The authors consider this method to be a useful non-invasive method for identifying of successful or unsuccessful PTCA in patients with coronary artery disease.