title: Irregular heart rates in two young children.
mesh_terms: D001024:Aortic Valve Stenosis / Q000150:complications; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D002648:Child; D003490:Cyanosis / Q000150:complications; D004562:Electrocardiography; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D011086:Polycythemia / Q000150:complications