Q waves infarction

On the other hand, we have to remind that Q wave of infarction may be seen in absence of infarction (Q wave without infarction) (see Differential di-... 

As we have previously affirmed, predominantly subendocardium infarctions can generate an infarction Q wave if they affect subepicardium areas of the ventricular wall that are in contact with the subendocardium, even though the wall is not homogeneously or necessarily transmurally affected. This occurs because in these situations a vector of infarction can arise (Q wave) (Figure 5.2C). Only when the stimulus reaches normal areas will an R wave be generated (QR complex). 

According to the vector of infarction theory, the infarction Q wave is of the same magnitude but in opposite direction to the one normally generated by the infarcted area (Figure 5.3B, C). The vector of infarction, thus, moves away from the infarcted area (see Figs. 5.3-5.5). For this reason, the beginning of ventricular depolarisation changes its... 

Bearing all this in mind, we study the correlation between the infarcted area in different walls due to occlusion in different locations of three coronary arteries (STE-ACS evolving to Q-wave MI) and leads with infarction Q waves based on two standpoints (1) from the CMR to ECG, and (2) from the ECG to CMR. 

A thorough assessment of II, III and VF provides useful information about anteroseptal involvement in the cases of apical-anterior MI. If infarction Q waves are present in II, III and VF, the infarction of inferior wall probably equally or predominantly involves this wall with respect to the anterior wall (very long LAD). If tall R waves are present in II, III and VF, the inferior involvement is probably small or absent (short 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. 

The VCG has been used to locate the presence of multiple infarctions. However, this technique is rarely used in daily practice. Furthermore, as we have already stated, it has been demonstrated that practically the same information may be obtained if the ECG-VCG correlation is used to understand ECG morphologies, as is done in this book (Warner et al., 1982). We need to also have in mind that, in some cases of single infarction, Q waves in leads of different areas may be seen, e.g. in an apical infarction due to a distal LAD occlusion, in addition to Q waves in the precordial leads these may also be seen in the inferior wall when the LAD is very long and there is infarction of the inferior wall that may be even greater than the anterior involvement (Figure 5.16). 

Differential diagnosis of an infarction Q wave Q wave or equivalent without Ml (Figures 5.41-5.43)... 

The late activation of some areas of the LV due to delay in activation of this area explains the late QRS complex forces opposed to the infarction Q wave. This was related for many years as peri-infarction block . Currently, the combination of an infarction with some intraventricular zonal blocks is based on the concept of the hemiblocks, defined by Rosenbaum, Elizari and Lazzari (1968). Because hemiblocks are diagnosed mainly by the changes in the vector s direction in the FP, the electrocardiographic changes secondary to the association with MI will be evidenced also specially in the FP leads. 

The disappearance of the infarction Q wave may be the result of an improvement of the disease (Figure 8.5). Generally, this is due to the presence of collateral vessels. The involved area may recover its... 

These are patients with an ACS evolving towards a low-risk UA or small infarction (Q-wave or non-Q-wave). Currently, the 30-day mortality rate is less than 3%. 

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