Early identification of impaired myocardial reperfusion with serial assessment of ST segments after percutaneous transluminal coronary angioplasty during acute myocardial infarction

To evaluate the relation between ST-segment analysis and microvascular repe rfusion. in patients with acute myocardial infarction (AMI), we studied 51 patients with first AM who were successfully treated by percutaneous transl uminal coronary angioplasty (PTCA). The lead showing the greatest ST-segmen t elevation. on the 12-lead electrocardiogram (ECG) was serially investigat ed until 24 hours after PTCA. Successful reperfusion was determined by tech netium-99m tetrofosmin single-photon emission computed tomography. Impaired reperfusion (group 1: <4 change in the sum of the defect score from before to immediately after PTCA) was observed in 24 patients, and successful rep erfusion (group 2) was observed in 27 patients. Although ST-segment elevati on was reduced significantly at 30 minutes after PTCA in group 2 (2.2 +/- 1 .4 to 1.7 +/- 1.3 mm, p = 0.01), there was no significant change in group 1 (1.9 +/- 1.9 to 2.4 +/- 1.7 mm). Ten of 14 patients (71%) with persistent ST-segment elevation (<Delta>ST >0 mm change in ST segment from before to 3 0 minutes after PTCA >0) were in group 1, whereas 23 of 37 patients (62%) w ith ST-segment resolution (Delta ST less than or equal to0) were in group 2 . The sensitivity and specificity of persistent ST-segment elevation for pr edicting impaired microvascular reperfusion were 42% and 85%, respectively. Thus, persistent ST-segment elevation 30 minutes after primary PTCA was a highly specific electrocardiographic marker of impaired reperfusion in pati ents with AMI. (C)2001 by Excerpta Medica, Inc.