Anterior infarct

A hypertensive crisis and myocardial infarction occurred in a 62-year-old woman after a combined injection of hydromorphone 48 mg and clonidine 12 mg subcutaneously in an attempt to refill an implanted epidural infusion pump (42). She was immediately treated with naloxone, but she subsequently had accelerated hypertension, a brief tonic-clonic seizure, and an anteroseptal myocardial infarction. Cardiac catheterization showed no coronary narrowing or blockage, but an anterior infarct was confirmed. 

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...

Figures 5.13-5.17). This electrocardiographic pattern corresponds to the so-called apical-anterior infarction. Compared to the A-l pattern, it exhibits a Q wave (QS or qr morphology) beyond lead V2 and usually beyond V3. 

It is called apical-anterior infarction because it corresponds to infarcted area usually... 

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...

Figure 5.16 (A, B) Example of apical-anterior infarction seen in cases of apical-anterior Ml with anteroseptal with inferior involvement equal to or greater than the involvement greater than the inferior involvement (C).

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). 

Electrocardiographic pattern of apical-anterior infarction (Figure 5.9A(2))... 

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. 

The smallest apical-anterior infarctions due to very distal LAD occlusion often do not exhibit... 

Sometimes there is an rS morphology in VI-V2 with Q in other precordial leads. This corresponds to apical-anterior infarction with more lateral than septal involvement (R wave in Vl-V2). 

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... 

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... 

It has already been stated that in some large anterior infarctions, no Q wave is seen in I and VL. This may occur in cases of proximal occlusion of a very long LAD, which may cause an inferior infarction that counterbalances the Q wave of the infarction of the mid-anterior area (Takatsuet al., 1988 Takatsu, Osugui and Nagaya, 1986) (Figure 5.7B). 

A-4. Electrocardiographic pattern type A-4 (Figure 5.9-A4) Q wave in VL and often I without abnormal q in V6 and, sometimes, with a q wave in V2-V3 (Figures 5.20-5.22). It corresponds to the mid-anterior infarction. 

It is called mid-anterior infarction because it corresponds to an infarcted area that mainly involves the mid-anterior wall with extention to mid-lateral wall and also to the basal and low-anterior and low-lateral wall. It involves segment 7 and parts of segments 13 and 12, and, on occasion, parts of segments 1 and 16 (Figures 5.20 and 5.21). 

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). 

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. 

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. 

The mid-anterior infarction produced by D1 occlusion (segments 7 and 12, especially) may exhibit a QS pattern in VL. This sign is specific but not very sensitive. When the infarction is small, a Q wave is usually seen, but often with a QR pattern (QR) with normal morphology in V5-V6 (Figure 5.21). On the contrary, a lateral infarction due to LCX occlusion (OM) (segments 5, 6, 11 and 12 in particular) may sometimes... 

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 5.39 (A) Apical-anterior infarction in subacute phase. Observe QS in V2-V3 with ST-segment elevation and small ST-segment elevation in II (occlusion distal to S1 and D1) (see p. 1.80). (B) Six months later another infarction occurs with appearance of r in V1-V3 and mild... 

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 5.56 Mid-anterior infarction associated with an SAH (A) the vector of the first part of the activation (that is the sum of vector 1 - which is generated in A + C areas -plus the infarction vector (Inf. V) (which moves away from VL) is opposite to the final vector of the ventricular...

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