New and Simplified ECG Classification for Myocardial Infarction


 Quintiliano H. de Mesquita, M.D.


The actual clinical cardiology demands an early and sure recognition about the participation of right ventricular infarction in front of recent studies on pathophysiological and therapeutic implications, which demonstrate the need for a different approach from that applied in the left ventricular infarction. Taking in consideration that the usual ECG classification for MI cover exclusively the infarction of left ventricle we developed a new and simplified classification which is based in the 'ECG Vectorial Theory for MI'.

 This new classification includes 3 infarction types, as follow:

 Type 1 - Left ventricular infarction, isolated: primary patterns of infarction (abnormal "Q" or "QS" waves); RS-T segment (+) and T wave (+, +- or -) in one or more left precordial leads (V1-V6) are registered in all types of left ventricular infarction except the pattern of inferior infarction pure, in combination with the classical patterns of infarctions from anterior walls (Q1aVL and T1aVL) or inferior (Q3aVF and T3aVF). The leads V4R, V5R and V6R from the right ventricular area show normalcy or they are local of secondary patterns of infarction (tall "R" wave).

 Type 2 - Right ventricular infarction, isolated or associated to not apparent infarction of left ventricle: primary patterns of infarction in one or more right anterolateral and precordial leads (V1-V4R, V5R, V6R) in combination with the inferior infarction pattern (Q3aVF and T3aVF). The V1-V6 leads from the left ventricular area show normalcy or they are local of secondary patterns of infarction in V5 and V6 (tall and relatively broad "R" wave).

 Type 3 - Left and right ventricular infarction, associated: primary patterns of myocardial infarction, simultaneous, in the area of the left ventricle leads (V1-V6) and in the area of the right ventricle leads (V1-V6R) in combination with the pattern of inferior infarction (Q3aVF and T3aVF) or anterior infarction (Q1aVL and T1aVL) in the limb leads.

Related articles and electrocardiographic images are at:

ECG Vetorial Theory of the Myocardial Infarction