Grade 3 ischemia on the admission electrocardiogram predicts failure of ST resolution and of adequate flow restoration after primary percutaneous coronary intervention for acute myocardial infarction

Evaluation of depolarization changes during acute myocardial ischemia by analysis of QRS slopes

“…In the Sclarovsky-Birnbaum ischemia grading system, loss of antero-septal S-waves during anterior STEMI, and changes in the R-wave amplitude/ST-J point ratio in inferior STEMI, respectively, indicate more severe ischemia, less salvage, worse microvascular flow, failure of ST-segment resolution and worse prognosis (8,10,11).…”

“…Some of these changes are considered to represent already necrotic areas (Q waves), but other, potentially reversible changes in the QRS complex also appear, although they are less well understood and are usually not considered for clinical decision making. Earlier studies on depolarization changes during ischemia due to acute coronary occlusion have considered QRS prolongation (1)(2)(3)(4)(5), amplitude changes of the R-and S-waves (4,6,7), "distortion" of the terminal part of the QRS complex (8)(9)(10)(11)(12) as well as changes in the high-frequency components of the QRS complex (13)(14)(15).…”

“…In the Sclarovsky-Birnbaum ischemia grading system distortion of the terminal part of the depolarization, in addition to pronounced ST elevation (grade 3 ischemia), has in several studies been found to be a sign of more severe myocardial ischemia and predict larger infarct size, lesser degree of ST-segment resolution, impaired microvascular patency and worse clinical outcome after revascularization by either thrombolysis or primary PCI (8)(9)(10)(11). These changes have been reported to be stronger predictors of clinical outcome than ST measures alone.…”

Coronary thrombus in patients undergoing primary PCI for STEMI: Prognostic significance and management

“…Prediction of thrombus burden and composition, as well as plaque volume and composition, before the procedure in patients with STEMI undergoing PPCI, may contribute to optimize percutaneous treatment of these highly thrombotic lesions, guiding utilization of pharmacological agents or interventional strategies, in order to reduce thrombus burden and improve both epicardial and myocardial perfusion. Grade Ⅲ ischemia on electrocardiogram, defined as distortion of the terminal portion of the QRS complex, and red cell distribution width (RDW), a marker of variation in the size of circulating red cells routinely reported as a part of blood count analysis, were shown to be independent predictors of coronary thrombus burden in STEMI patients undergoing PPCI, and to be associated with angiographic no-reflow and impaired epicardial and myocardial perfusion [39][40][41] . Probably, also the evaluation of thrombus burden using, not only coronary angiography, but also intravascular imaging modalities, such as ultrasound, optical coherence tomography or virtual histology, may provide important informations about the amount and composition of coronary thrombi, thus facilitating the choice of treatment strategies.…”

The usefulness of fQRS and QRS distortion for predicting reperfusion success and infarct-related artery patency in patients who underwent thrombolytic therapy

“…Previous studies have shown that fQRS and QRS distortion were used to determine inadequate reperfusion in acute STEMI patients who underwent primary PCI [22,23]. However, the relationship between fQRS and QRS distortions with the success of electrocardiographic and angiographic reperfusion has not been compared previously in acute STEMI patients who underwent TT.…”