Atypical electrocardiographic presentations of myocardial infarction with ST elevation - ST elevation myocardial infarction equivalents

Abstract

Introduction. Some patients with clinical symptoms and signs of acute myocardial and coronary artery occlusion have atypical electrocardiographic presentations-ST elevation myocardial infarction equivalents. Rapid recognition of these patterns is imperative, because the condition requires prompt reperfusion therapy following actual guidelines. De Winter pattern. Diagnostic criteria are: tall, prominent, symmetrical T-waves in the precordial leads, upsloping ST segment depression > 1 mm at the J-point in the precordial leads, absence of ST elevation in the precordial leads, ST segment elevation (0.5 mm-1 mm) in aVR. ST Elevation in aVR. Electrocardiographic criteria include ST segment elevation in aVR ≥ 1 mm, ST segment elevation in aVR ≥ V1, and diffuse ST segment depression in lateral leads. Wellens syndrome. Wellens syndrome describes deeply inverted or biphasic T-waves in leads V2-V3, highly specific for significant stenosis of the left anterior descending artery. Posterior infarction. Posterior infarction is confirmed with ST segment depression ≥ 0,5 mm in leads V1-3 and ST segment elevation ≥ 0.5 mm in posterior leads (V7-V9). Conclusion. There are many electrocardiographic patterns that physicians should promptly recognize as clinical myocardial infarction with ST segment elevation equivalents in order to perform urgent reperfusion therapy for better prognosis and survival in these patients.

Particular electrocardiographic phenotypes in acute coronary syndromes

“…In some cases there is poor R wave progression in precordial leads [15]. Unlike hyperacute T waves occuring within minutes after acute coronary occlusion and rapidly evolving towards ST segment elevation, de Winter T waves are not transient, instead they persist on subsequent tracings [17]. The prevalence of this pattern is about 2% of the patients with MI and angiographically proven LAD occlusion, both in the initial study of de Winter and Wellens in 2008 (30/1,532 pts) [15] and in Verouden`s study in 2009 (35/1,890 pts) [18].…”