Abstract
In 56 patients, the QRS voltage and the AQRS were compared before and after the development of LBBB with particular reference to LVH. The QRS voltage was frequently de-creased, occasionally unchanged and rarely in-creased with the appearance of the conduction defect. The AQRS was unchanged in the majority of patients studied. The probable cause of these changes were discussed. Our results support the conclusion of others in that this diagnosis can be made in many only by inference. It was also re-emphasized that the significance of the AQRS deviation in LBBB in the same as that in normal conduction.
