Intracoronary electrocardiogram for early detection of myocardial viability during coronary angioplasty in acute myocardial infarction

Purpose: The clinical value of the intracoronary electrocardiogram (ECG) fo r detecting myocardial viability in acute myocardial infarction was evaluat ed by thallium-201 scintigraphy and left ventriculogram at the chronic stag e. Methods: Intracoronary ECGs, recorded froth the tip of a guidewire durin g emergency coronary angioplasty, were obtained in 65 patients with reperfu sed anterior myocardial infarction. Further ST segment elevation of greater than 0.2 mV detected during the balloon inflation was taken as significant . The left ventricular segmental shortening was measured from left ventricu lograms recorded at acute and chronic stages. The infarct area was defined as viable when a thallium uptake of more than 50% was detected on thallium- 201 myocardial scintigraphy at the chronic stage. Results: During emergency coronary angioplasty, significant ST segment elevation was noted in 45 pat ients (Group A); however, the ST segment was not significantly elevated in the other 20 patients (Group B). The infarct area of 42 patients in Group A and three patients in Group B was viable on scintigraphy. Improvement left ventricular wall motion of the infarct area was observed in 39 of the 42 p atients in Group A and the three patients in Group B. Therefore, intracoron ary ECG can predict reversible dysfunction with excellent sensitivity (92.9 %) and specificity (73.9%). Conclusions: The myocardium within an infarct a rea can be regarded as viable when a further ST segment elevation occurs on intracoronary ECG during emergency coronary angioplasty. It is useful, the refore, to monitor the intracoronary ECG during coronary angioplasty balloo n inflation to assess the myocardial viability of the infarct area. (C) 200 1 Elsevier Science Ireland Ltd. All rights reserved.