Extensive anterior infarction

Occlusion proximal to the SI branch but distal the D1 branch (Figure 4.25 and Table 4.1A(4)) When the occlusion is located above, the SI but not the D1 (Figure 4.25), which rarely occurs (<15% of the STE-ACS), the area at risk could lead to a relatively extensive anterior infarction when the D1 branch is quite small and the D2 branch is large. However, usually more septal and anterior than lateral involvement is seen (Figure 4.25B,C). Currently, with the new treatments employed in the acute phase, most of these cases end up being just an apical infarction... 

Figure 5.4 (A) Observe the comparison between the normal activation and the activation in case of an extensive anterior infarction. The vector of infarction is...

A-3. Electrocardiographic pattern type A-3 (Figure 5.9-A3) Q waves from VI to V3-V6, I and/or VL (Figures 5.18 and 5.19). This pattern corresponds to extensive anterior infarction. Compared to the A-2 pattern, this one also exhibits a Q wave (QS or QR) in VL and, sometimes, in lead I. 

It is called extensive anterior infarction because it corresponds to large areas of not only the anterior and septal walls, but also the low- and... 

The pattern of the extensive anterior infarction is usually explained by proximal LAD occlusion,above the take-off of the SI and D1 branches. Naturally, the infarction also extends to the apical area and here the four walls are always involved (except when the LAD is very short). But the difference with the apical-anterior infarction lies in that in the latter although an-teroseptal wall maybe involved, the basal portion of LV is spared and the involvement of lateral wall is lesser. The extensive anterior infarction, on the other hand, reaches the mid-lateral wall and the basal areas in some walls, generally the anterior and septal walls, but not lateral wall (Figure 5.18), because as we have already said the basal segments of lateral wall, even the anterior portion, are perfused by the LCX (OM) (see Figure 5.4C). 

In this case, significant extensive anteroseptal involvement, especially the middle and lower portions, and also lateral involvement (mid-low wall), explains that the infarction vector is directed posteriorly rightwards and sometimes downwards (Figure 5.35), and generates a loop that usually rotates clockwise in the FP, but in HP rotates clockwise (QR in V6) (Figure 5.19) or counter-clockwise (RS in V6) (Figure 5.35). Therefore, a Q wave is seen in most of the precordial leads, VI to V4—V6 and in VL and I, QR or RS pattern maybe seen (Figures 5.19 and 5.35). The pattern of extensive anterior infarction with... 

Some limitations exist in the presence of Q waves in the precordial leads with respect to knowing the real extension of the infarction. This is especially true when distinguishing between the apical-anterior infarction (type A-2) and the extensive anterior infarction (type A-3). 

Infarctions with a Q wave in V1-V4 and sometimes qrs or qR in V5-V6 usually with a negative T wave correspond to apical-anterior infarction (distal occlusion of LAD) with or without anteroseptal extension, and most of the cases that in addition to having a Q wave in the precordial leads exhibit QS or QR patterns in VL (and/or lead I) corresponding to an extensive anterior infarction (proximal occlusion of LAD). 

In a few cases, the electrocardiographic patterns of apical-anterior infarction (Q wave in the precordial leads, but not in leads I and aVL) correspond to extensive anterior infarctions (Figure 5.7). Additionally, in some rare cases, electrocardiographic patterns of extensive anterior infarction (Q wave in the precordial leads and I and aVL) correspond, in fact, to apical-anterior infarctions. 

In case of IPH associated with an extensive anterior infarction including mid-anterior wall, the vector of infarction (B) counteracts the initial depolarisation vector (1) (Figure 5.57) and generates a change in the QRS loop that is directed rightwards and downwards. Thus, it explains the QS morphology in I and VL (Figure 5.57). 

Figure 5.57 Extensive anterior infarction including mid-anterior wall associated with IPH (A) the first ventricular depolarisation vector (1) generated in A + B areas in case of isolated IPH is directed upwards. However in case of extensive anterior infarction plus IPH, the infarction vector (Inf. V) is more important than the first depolarisation vector and all the loops move away from the infarcted area in the same direction of the second...

Figure 8.12 Patient with extensive anterior infarction. ECG normalisation with Q wave disappearing and positivation of T wave during 18-month follow-up.

A 22-year-old man with a 6-year history of intravenous heroin use was maintained on methadone 60 mg/day and dihydrocodeine 0.5 g/day. He had an extensive anterior myocardial infarction as a result of occlusion of the left anterior descending coronary artery, which was reopened by percutaneous transluminal coronary angioplasty. 

The typical apical-anterior infarction is a consequence of LAD occlusion, clearly distal to the D1 and SI. If there is anteroseptal extension, it is usually due to non-complete LAD occlusion im-... 

In some infarctions with QS pattern from VI to V4, the presence of a Q wave is observed in II, III, and VF, with qr or QS pattern. This occurs in typical apical infarctions, but not in case of important anteroseptal extension (Figure 5.16), since in the former, inferior infarction is frequently as important or more than anterior infarction, with the infarction vector of inferior wall and the corresponding loop in the FP, being directed upwards (Figure 5.16A). In... 

Figure 5.15 The ECG pattern of apical-anterior infarction (type A-2) with important anteroseptal extension as may be seen in this example but preserving the basal area of septum (D) and anterior wall (E). The lateral extension only involves the low part (D). The lack of involvement of segment 12 and lesser involvement of segment 7 are the...

A Q wave in VI to V3-V6 may be seen in apical-anterior infarction with or without anteroseptal extension. The presence of a Q wave in II, III and VF supports that inferior infarction being equal to or more important than anterior infarction is a typical apical infarction. 

On rare occasions apical-anterior infarctions especially with anteroseptal extension that corresponds to A-2 pattern presents with an ECG of type A-3 (extensive anterior), because an abnormal pattern is recorded not only in precordial but also in leads I and VL (QS and QR patterns). The changes caused by cardiac rotation (levorotation) or the presence of LVH, among other factors, may at least partially explain it. In the levorotated and... 

As regards the infarcted area, apical-anterior infarctions do not affect a large portion of the left-ventricular lateral wall, while in extensive anterior this wall is more affected. 

The QS morphology in VL without Q in V5— V6 is due to a mid-anterior infarction with mid-low lateral wall extension (first diagonal... 

Figure 5.47 Patient with complete RBBB and myocardial infarction type A-3 (extensive anterior Ml). Observe the Q wave in precordial leads and the QS morphology in VL. In CE-CMR images (A-E) show important involvement of lateral, anterior and septal walls, and even the lower part...

Figure 5.52 The ECG of a patient with complete LBBB and associated infarction. There are ECG criteria suggestive of extensive anterior myocardial infarction (qR in I, QR in VL and low voltage of S in V3). The CMR images (A-D) demonstrated the presence of an extensive infarction of anteroseptal zone (type A-3) (proximal LAD occlusion). The inferolateral wall is free of necrosis (see (D)), because the...

We will just remind (see p. 137) that seven areas of MI detected by CE-CMR have good correspondence with seven ECG patterns (four in anteroseptal zone - septal, apical-anterior, extensive anterior and mid-anterior - and three in the inferolateral zone - inferior, lateral and infero-lateral) (Figure 5.9 Cino et al., 2006). We have also demonstrated that in clinical practice the presence of these seven ECG patterns correlates well with the corresponding infarction areas detected by CE-CMR, and therefore these have real value in clinical practice (Bayes de Luna et al., 2006a-c) (Table 5.3). Therefore, in chronic infarction the correlation between ECG changes (Q waves of necrosis) and involved area (CE-CMR) is clearly good (88% global concordance). However, the in-farcted area of apical infarction (A-2 type), mid-anterior infarction (A-3 type) and lateral infarction (B-l type) presents the lower concordance. 

Electrocardiographic pattern type A-2 (Figure 5.9-A2) Q wave in Vl-V2to V4-V6 (Figures 5.13-5.17). This corresponds to apical-anterior infarction. At times, the extension of the infarction involves upper areas especially of the anterior and... 

Figure 10.6 Patient with an extensive anterior Ml in the subacute phase (QS-and ST-segment elevation in all the anterior leads and, additionally, a QR complex in I and VL). A PR-segment depression in II, with PR interval elevation in VR, is seen. These changes and the presence of frequent atrial arrhythmias suggest the atrial extension of the infarction.

Takatsu F, Osugui J, Nagaya T. Is it possible to rule out extensive anterior myocardial infarction in the absence of abnormal Q wave in lead I and a VL Effect of inferoapi-cal extension of infarction over apex. Jpn Circ J 1986 50 601. 

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