RESUMO
<p><b>OBJECTIVE</b>To evaluate the role of intracoronary electrocardiogram (IcECG) in examining early myocardial injury during percutaneous coronary intervention (PCI).</p><p><b>METHODS</b>Eight-six patients who had undergone elective PCI for their coronary heart disease were enrolled in the study. The IcECG both at baseline and after procedure were recorded with an incoronary guidewire and the serum levels of cardiac troponin T (cTnT) and creatine kinase-myoglobin were measured at baseline and 8 and 24 hours after intervention. Myocardial damage was defined as serum levels of cTnT increase above the upper normal value after intervention. Cardiac events after intervention was followed up.</p><p><b>RESULTS</b>Of all these 86 patients with normal serum levels of cardiac markers before the procedure, significant shift at ST-segment in IcECG during PCI was observed in 30 patients (35%, abnormal group) and no shift in the remaining 56 patients (65%, control group). All the procedures were successful. Serum levels of cTnT and creatine kinase-myoglobin were significantly higher in abnormal group than in control group after intervention (P < 0.01). The intracoronary ST-segment shift had a sensitivity of 77% and a specificity of 94% in predicting myocardial injury, with positive and negative predictive values of 90% and 86%, respectively. More cardiac events were observed in abnormal group than those in control group at a 4-week follow-up after intervention (P < 0.05) and major coronary event-free survival was significantly lower in those with post-procedural ST-segment shift in the IcECG (P < 0.05).</p><p><b>CONCLUSION</b>IcECG may be a useful method for predicting myocardial injuries during PCI.</p>