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Figure 3 (A) This figure shows a user-defined map of the infero-posterior wall of the left ventricle (LV), including the LV apex and the mitral valve annulus (MVA). As in Figure 2A, the electrogram (EGM) width is color-coded. The patient had an inferior myocardial infarction one year before the mapping study. The EGM shown is the broadest endocardial EGM obtained in this patient and represents the site of effective ablation of the targeted ventricular tachycardia during sinus rhythm. The EGM width is 150 ms; an isoelectric segment of 26 ms separates the ventricular EGM from the isolated potential (arrow). (B) The scheme represents a view of the same area outlined in panel A. The striped area corresponds to areas with low-voltage EGMs, and the black area represents the contiguous area with an EGM width of >133 ms. The white area correspond to sites with higher voltage electrograms (>1 mV). Black area = EMG >133 ms; striped area = EGMs <1 mV; white area = EGMs >1 mV. (C) This figure illustrates the voltage map of the same view outlined in panels A and B in this patient, delineating the low-voltage areas from areas with higher voltage (>1 mV).