title: Electrophysiological properties of the atrioventricular node and ageing: evidence of a lower incidence of dual nodal pathways in the elderly.
abstract: OBJECTIVE
  The purpose of this study was to investigate the relationship between the incidence of dual atrioventricular (AV) nodal pathways and age. Age-related changes in the AV node electrophysiological properties have rarely been investigated. AV nodal re-entrant tachycardia is more frequent in the young than in the elderly.
  
  
  RESULTS
  From 1988 to 1998, premature atrial stimulation was performed in 1,435 patients referred to our institution for transoesophageal electrophysiological study. 1,276 patients (89%) with a diagnosis of ventricular pre-excitation, supraventricular arrhythmia or AV block were excluded. The study cohort consisted of the remaining 159 patients (11%) of the whole group) referred for syncope (8.2% of the subgroup), suspected ventricular pre-excitation (10.7%), suspected sinus node dysfunction (52.8%) or undetermined palpitations (28.3%). The 159 study patients were divided into 3 groups according to age: group A (11-30 years, 50 patients), group B (30-60 years, 35 patients) and group C (>60 years, 74 patients). A dual AV nodal pathway was found in 16 patients of group A (32.0%), 6 patients of group B (17.1%) and 8 patients of group C (10.8%), the difference between group A and group C being significant (P<0.05).
  
  
  CONCLUSIONS
  The incidence of dual AV nodal pathways decreases with ageing, suggesting that the AV node undergoes age-related electrophysiological changes. This finding could explain the uncommon onset of AV nodal re-entrant tachycardia in the elderly.
authors.affiliation: Cardiology Department, Ospedale Civile, Mirano, Venice, Italy. ulss13mir.card@tin.it
authors.forename: D
authors.initials: D
authors.lastname: D'Este
authors.forename: E
authors.initials: E
authors.lastname: Bertaglia
authors.forename: A
authors.initials: A
authors.lastname: Zanocco
authors.forename: B
authors.initials: B
authors.lastname: Reimers
authors.forename: P
authors.initials: P
authors.lastname: Pascotto
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001283:Atrioventricular Node / Q000502:physiology*; D002648:Child; D015331:Cohort Studies; D022062:Electrophysiologic Techniques, Cardiac; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology