Distortion of the terminal portion of the QRS is associated with poor collateral flow before and poor myocardial perfusion after percutaneous revascularization for myocardial infarction

Abstract

The distortion of the terminal portion of the QRS has been related to adverse outcome in patients with ST-segment elevation myocardial infarction. 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. 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). 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.