RESUMO
AIMS: The distortion of the terminal portion of the QRS has been related to adverse outcome in patients with ST-segment elevation myocardial infarction. METHODS: We studied the relationship of this electrocardiographic pattern with the angiographic findings in patients treated with percutaneous revascularization for ST-segment elevation myocardial infarction. We included 349 patients, 318 treated with primary angioplasty and 31 with rescue angioplasty after failed thrombolysis. RESULTS: Eighty-five patients were found with distortion of the terminal portion of the QRS complex (group 1) and 264 without it (group 2). Collateral flow was absent in 30 patients (35%) from group 1, versus 52 patients (20%) from group 2 [odds ratio (OR) 1.806, 1.097-2.974, P 0.019]. No-reflow occurred in 12 (14%) patients in group 1 versus 17 (6.4%) in group 2 (OR 2.388, 1.091-5.230, P 0.016). Myocardial perfusion was graded 2-3 in 28 patients (58%) of group 1 versus 98 (76%) in group 2 (OR 0.443, 0.220-0.893, P 0.021). CONCLUSION: Patients with ST-segment elevation myocardial infraction showing distortion of the terminal portion of the QRS have worse collateral flow, and present more often no-reflow or poor myocardial perfusion after percutaneous revascularization. These data contribute to explain the worse clinical outcome of these patients.