title: Narrow QRS complex tachycardia with alternating shorter and longer R-R cycles: what is the mechanism?
authors.affiliation: Third Department of Internal Medicine, Semmelweis University, School of Medicine, Budapest, Hungary. vereckei@kut.sote.hu
authors.forename: Andras
authors.initials: A
authors.lastname: Vereckei
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000473:pathology; D006801:Humans; D011226:Pre-Excitation Syndromes / Q000175:diagnosis*; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis*