title: Unusual type of preexcitation. I. Short P-R interval.
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001283:Atrioventricular Node / Q000503:physiopathology; D004562:Electrocardiography; D006801:Humans; D009434:Neural Pathways / Q000503:physiopathology