title: Letter: ECG and the A-V bundle.
mesh_terms: D000200:Action Potentials; D006332:Cardiomegaly / Q000503:physiopathology; D004562:Electrocardiography; D006321:Heart / Q000294:innervation / Q000502:physiology / Q000503:physiopathology; D006327:Heart Block / Q000175:diagnosis* / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male