Q wave myocardial infarction of anteroseptal zone: A new classification (original) (raw)

International Journal of Cardiology, 2015

Abstract

ABSTRACT Studies comparing Q waves of necrosis in antero-lateral leads with the site and extent of myocardial infarction (MI) at contrast-enhanced cardiac magnetic resonance show that patients can be clustered into four different locations of MI. 1) Septal MI. In these patients Q waves are present in leads V1-V2 and an MI scar is located in the interventricular septum. Sensitivity 100%; specificity 97%. Due to the great variability in coronary artery distribution and because the diagnosis depends on the presence of Q wave in lead V3, the sensitivity and specificity may change unless a strict methodology of positioning of precordial electrodes is followed. 2) Apical-anterior MI. In such a case Q waves are present from leads V1-V2 to V3-V6 and MI scars are located in the anterior wall and apex. Sensitivity 85%; specificity 98%. If the inferior involvement is large, Q waves in leads II, III and aVF are frequently associated. Even in the absence of inferior Q waves, 13% of the "anterior" infarction scar is extended to the inferior and/or inferoseptal apical segments, and 6% is extended to the lateral apical segment. 3) Mid-anterior MI: In these patients Q waves, QS or qr complexes are present in lead aVL and/or I, and sometimes in leads V2-V3. In the past this pattern was considered to correspond to a high lateral MI, involving the portion of the LV lateral wall perfused by the left circumflex artery or the obtuse marginal branch. More recently, this pattern has been found to correspond to a mid-anterior MI, involving the portion of lateral wall perfused by the first diagonal branch. Sensitivity 67%; specificity 100%. 4) Extensive anterior MI: In this case Q waves appear both from leads V1-V2 to V4-V6, and in leads I and aVL. This pattern suggests that the infarction scar is more extensive than the apical zone, also involving the anterior, septal and mid-low lateral walls. Sensitivity 83%; specificity 100%. Finally, the greater the number of anterior Q-waves, the larger the MI size and its transmural extent. This classification is limited by the variability in coronary artery distribution, in the anatomical and electrical orientation of the heart inside the thorax, and finally, by a possible misplacement of precordial electrodes.

Alessandro Pingitore hasn't uploaded this paper.

Let Alessandro know you want this paper to be uploaded.

Ask for this paper to be uploaded.