[Septal displacements during  intraventricular conduction disorders. Echocardiographical study].
We have analysed the echocardiograms of ten healthy subjects, sixty patients with disorders of intra-ventricular conduction, and ten who were treated by a temporary intracavitary pacemaker. There was found to be a pre-ejection displacement of the septum towards the posterior wall, beginning just after electrical depolarisation of the ventricle followed, in most cases, by 'paradoxical' displacement towards the anterior wall during systole. Such a displacement, producing a 'beaked' image on the echocardiogram, is only found when the ventricular complexes have the characteristics of complete left bundle branch block (LBBB), whether this is spontaneous LBBB or a functional LBBB produced by an intracavitary pacemaker. The results support the hypothesis that the posterior displacement of the septum in cases of LBBB is related to abnormal spread of excitation. Under these conditions, during the pre-ejection period the septal forces predominante over those of the free wall of the left ventricle. In a patient with LBBB who had failed to show this typical septal displacement in several investigations, the 'beak' of the septum could be observed only when the electrical axis deviated to the left, and when the QRS complex exceeded 0.14/s to 0.16/s, this condition being fulfilled because the LBBB was really complete at the time of the last investigation.
D000368:Aged; D002037:Bundle-Branch Block / Q000503:physiopathology*; D004452:Echocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006346:Heart Septum; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged
Les déplacements du septum au cours des troubles de conduction intra-ventriculaire. Etude échocardiographique.