title: Left anterior hemiblock masking the diagnosis of right bundle branch block.
abstract: A case is presented in which left anterior hemiblock obscured totally the diagnosis of right bundle branch block by abolishing the S wave in leads 1 and aVL, and terminal R wave in leads V1 and V2. The presence of right bundle branch block was confirmed by recording high V1 and V2 leads. Subsequently, the ECG revealed how a greater degree of conduction delay in the right bundle branch may uncover the previously concealed right bundle branch block. The electrocardiographic features of these findings are discussed.
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis