UNLABELLED: Aim Ischaemia modified albumin (IMA) is considered a marker of myocardial ischaemia, in contrast to the biomarkers of myocardial injury [creatine kinase (CK), the MB isoenzyme of CK, and cardiac troponin I (Tn-I)] that are released when cardiac necrosis occurs. Ischaemia modified albumin has been reported to increase following percutaneous coronary intervention and in acute coronary syndromes. We sought to determine whether IMA increases following radiofrequency (RF) ablation. METHODS AND RESULTS: We studied 40 consecutive patients who underwent RF catheter ablation; 20 were men and 20 women and their age was 47 +/- 16 (16-77) years. All patients underwent electrophysiological study and subsequent RF ablation. Peripheral venous samples were collected before the procedure (baseline), immediately after the procedure, 2 h post-procedure and the following day (20 h post-procedure) and assayed for CK, the MB isoenzyme of CK, cardiac Tn-I and IMA. Ischaemia-modified albumin plasma levels did not differ significantly at all four time points, baseline, and following ablation (P = 0.5974), whereas CK, CK-MB, and Tn-I increased significantly at all time points compared with baseline (P < 0.0001). Post-ablation, all but three 3 CK measurements were in the normal range; 14 patients had CK-MB plasma levels above the upper limit of normal; all but one patient had Tn-I elevated. CONCLUSION: The IMA plasma levels do not change significantly following RF ablation, unlike biomarkers of myocardial injury, implying that myocardial necrosis occurs without preceding ischaemia.