Preservation of pre-excitation despite acute myocardial infarction complicated by complete heart block.
In a 53-year-old man with ventricular pre-excitation (normal PR interval, QRS interval of 0.12 seconds and delta-waves) acute inferior wall myocardial infarction was complicated by, successively, first-degree atrioventricular block, second-degree atrioventricular block (Wenckebach type) and complete heart block. The QRS pattern of pre-excitation was preserved throughout these events. The classification of ventricular pre-excitation is reviewed and the correlation between the various electrocardiographic patterns (the Wolff-Parkinson-White syndrome and its variants and the Lown-Ganong-Levine syndrome) and the anomalous conduction pathways of Kent, James and Mahaim are discussed. In this case the best possible explanation for preservation of pre-excitation during complete heart block was the existence of accessory fibres of Mahaim.
D000208:Acute Disease; D004562:Electrocardiography; D006327:Heart Block / Q000150:complications* / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D014927:Wolff-Parkinson-White Syndrome / Q000503:physiopathology*