Inferoposterior wall

Figure 1.7 (A) The left ventricle may be divided into four walls that till very recently were usually named anterior (A), inferoposterior (IP) or diaphragmatic, septal (S) and lateral (L). However, according to the arguments given in this book, we consider that the inferoposterior wall has to be named just inferior (see p. 16). (B-D) Different drawings of the inferoposterior wall (inferior + posterior walls) according to different ECG textbooks (see inside the figure). In all of them the posterior wall corresponds to the...

Classically it was considered that the four walls of the heart are named septal, anterior, lateral and inferoposterior. The posterior wall represents the part of inferoposterior wall that bends upwards. 

However, (a) infarction of the inferobasal segment (posterior wall) does not usually generate a Q wave because it depolarises after 40 milliseconds (Durrer et al., 1970) (Figure 9.5). (b) Furthermore, the CMR correlations have demonstrated that the posterior wall often does not exist, because usually the basal part of the inferoposterior wall does not bend upwards (Figure 1.13). (c) In cases that the inferoposterior wall bends upwards, even if the most part of inferior wall is posterior, as may be rarely seen in very lean individuals, as the heart is located in an oblique... 

This corresponds to an inferior and/or lateral wall infarction (Figure 5.9B(l-3)). In this book, segment 4, which was traditionally known as the posterior portion of the inferoposterior wall, is named inferobasal segment of the inferior wall. The RS morphology in VI is due to an infarction of the lateral wall. 

Therefore, often, the posterior wall does not exist and for this reason, the name inferior wall seems clearly better than the name inferoposterior . On the other hand, the anterior wall is, in fact, superoanterior, as is clearly appreciated in Figure 1.1 IB. However, in order to harmonise the terminology with imaging experts and to avoid more confusion, we consider that the names anterior wall and inferior wall are the most adequate for its simplification and also, because when an infarct exists in the anterior wall, the ECG repercussion is in the horizontal plane (HP V1-V6) and when it is in the inferior wall - even in the infer-obasal segment - it is in the frontal plane (FP). 

Figure 5.8 Above Left side shows the involved area in case of inferior, posterior and inferoposterior Ml with the classical ECG patterns in chronic phase according to the old concept right side shows that with the new concept exposed in this book the name posterior disappears, the RS pattern in V1 is explained by lateral Ml and the Ml of the inferobasal segment of inferior wall (classically posterior wall) does not generate Q wave because it is a zone of late...

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