title: [Left atrial parasystole].
abstract: A case of atrial parasystole is described in a 55-year-old female with multivalvular heart disease, treated with high doses of digitalis and showing first-degree av block. The left atrial origin of the parasystolic P waves was supported by their distinctive morphology, especially in lead V1, and the sequence of left and right atrial activation. Depending on the refractory state of the myocard, there was a greater shortening of the av conduction time during the parasystolic discharge than during sinus beats indicating a caudal localization of the parasystolic center.
mesh_terms: D001145:Arrhythmias, Cardiac / Q000150:complications / Q000503:physiopathology*; D004071:Digitalis Glycosides / Q000627:therapeutic use; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006327:Heart Block / Q000503:physiopathology; D006349:Heart Valve Diseases / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged
chemical_list: D004071:Digitalis Glycosides
vernacular_title: Linksatriale Parasystolie