[A new classification of lower infarcts with important prognostic significance].

Background: The initial therapy of acute myocardial infarction is often determined by the electrocardiogram.
Objective: To evaluate a classification of inferior myocardial infarctions according to the first electrocardiogram.
Design and Setting: Prospective study in a coronary care unit.
Patients: 116 patients admitted due to a first acute myocardial infarction of the inferior wall.
Methods: "Type 1" electrocardiogram was defined as ST segment elevation without distortion of the QRS. Patients were considered "type 2" when, besides ST segment elevation, they presented a distortion of the terminal portion of the QRS complex in two inferior leads.
Main Results: Twenty-nine patients (25%) were considered "type 2". These patients were older and had worse Killip class than "type 1". The mortality rate was 1.2% in "type 1", and 24.1% in "type 2" (p = 0.0002). After multivariate analysis, which included Killip class, age, smoking, type of electrocardiogram and fibrinolysis, the type of electrocardiogram remained significantly predictive of death (p = 0.014).
Conclusions: We conclude that "type 2" electrocardiogram is an independent predictor of adverse outcome in inferior infarctions. Further investigation is needed concerning its implications in the clinical management of these patients, although reperfusion therapy is warranted.