[Septal and parietal dead myocardium with peripheral monofascicular blocks]

We describe the electrical manifestations of dead left septal, left and right parietal myocardium and those of biventricular location, reviewing the electrocardiographic signs of the isolated left and right peripheral blocks. We also describe the electrical manifestations of dead myocardium accompanied by a left anterior subdivision block (LASB) and a left posterior subdivision block (LPSB). These ventricular conduction disorders can reduce or conceal the electrical manifestation of the dead zone. We present a case in which a transient LASB conceals the electrical manifestation of dead anteroseptal myocardium. The association of diaphragmatic dead myocardium with LPSB reduces the electrocardiographic manifestation of dead tissue. We show the electrocardiographic findings obtained in a case of a biventricular anterior infarct with a right anterior subdivision block (RASB), as well as an ECG corresponding to the association of a dead myocardial zone with a right posterior subdivision block (RPSB). These ventricular conduction disorders do not generally conceal the electrocardiographic signs of dead myocardial tissue. The possible association of myocardial damage due to an infarct or a myocardiopathy with ventricular proximal and peripheral blocks must be kept in mind. Besides, it is important to consider that proximal blocks do not modify substantially the signs of dead myocardial tissue, whereas peripheral blocks can reduce or conceal these signs.