Clinical Observations on Defective Conduction in the Branches of the Auriculoventricular Bundle

The present communication is based on material collected in the Cardiographic Department of University College Hospital Medical School, London. It includes a description of twenty-two cases in which evidence of defective conduction in one or the other branch of the auriculoventricular bundle was observed electrocardiographically, a description of the characteristic features of aberrant curves and remarks on the clinical associations of the corresponding defects. As defective conductivity of the main stem of the auriculoventricular bundle gives rise to a characteristic electrocardiogram, so do lesions of its individual branches give rise to abnormal electrocardiographic curves, which, within certain limits, follow definite types. It is with these definitely known forms of abnormal curves that we are concerned. Asaberrant1are grouped those heart-beats which result as a direct sequence of impulses which arise in a supraventricular focus, but which reach the ventricle either through an unusual route or through